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Oil & Filter Change Procedures. Technical information.
BMW Airhead Motorcycles, ONLY.
Filters, shims, O-rings, canisters; external filter kits.
  This article includes very detailed information on what is often referred-to as
 "The $2000 O-ring" (which will become ~ TWICE that, if crankshaft is damaged).

Copyright, 2014, R. Fleischer


This is a VERY comprehensive article. 
You SHOULD ALSO READ oilcansimple.htm:

Failure to heed advice given in this article on measuring & assembly of parts in the oil filter canister area can cause SERIOUS damage. 


Your /5 and later BMW Airhead motorcycle lower-end has a well-deserved reputation for reliability & exceptionally long life.......if the engine is kept properly lubricated.  Regular oil & filter changes based on both oil quality, time, & mileage, are all required.  Over the years of Airhead production there were a fairly large number of different filter numbers, filter styles, methods of fitting them and associated parts such as O-rings, gaskets, shims, and oil cooler attachments.  This article will attempt to cover all versions,  all models,  all situations.   This is an in-depth and lengthy article.  It is intended to be THE place you will find ALL the information.   I expect you to read it all the way through at least once; then in the future use what parts of it that are pertinent.   The only other website I can refer you to that may be of some interest in this area is Anton Largiader's...a very good website.

OAK (Orlando Okleshen) an Airhead Guru of quite some reputation, wrote articles over many years covering some, if not most of this subject matter. Much of it was published in the magazine of the BMW Motorcycle Owners of America called BMWNEWS, now BMWMOA-ON. Those older issues may be difficult to find, and are no longer needed, as he treated the subject in depth, in AIRMAIL, the publication of the Airheads Beemer Club, in the June 1997 issue, with follow-ups in the July 1997 and the August 1997 issues. Most postings made after the June 1997 article will refer to this SUBJECT as the $2000 O-ring. Oak did an article in AIRMAIL in the August 2004 and September 2004 issues, with a somewhat different approach to explaining the problems and making the measurements, and those, if you have them or obtain them, are good articles to look at. The January 2008 issue of AIRMAIL has a good summary of Oak's approach, and that issue is recommended by me, as it is the latest AIRMAIL that has all the information you basically need.   The article you are now reading is very comprehensive, and covers everything.  Sometimes it is helpful to folks to read the same or similar type of information when it is said differently.  You can read such articles on such as the Technical Tips area of, etc.
You can also read:

Some folks understand the measuring better from other articles, some understand it better in MY article you are reading.    My method works, and is simple and easy to understand; it is also very SAFE to use my method.

Information published in the popular Haynes and Clymer's manuals MAY be wrong. Certainly some of it is confusing, not the least of which are errors in sketches in one version of the Haynes manual on the parts fitment in the oil canister area.

BMW themselves have published some information that is also misleading, to say the least. Some BMW sketches show parts that are not to be the outer paper gasket with cooler's (usually); and, sometimes BMW sketches have parts identified that are used for a wide variety of models/years, BUT not all the parts are used in, perhaps, YOUR bike.  This is particularly bad and confusing in Haynes and Clymers books.  That is because their writers and editors did not, it seems, understand what they were writing about.  It is sometimes what is NOT published that causes problems!!



If just changing the engine oil, and NOT the filter, take a 10 mile minimum ride to warm the oil.  On the center stand, remove the engine pan drain plug, drain the oil, replace the oil drain plug using a new crush washer, top up the oil to the proper mark (NOT screwing in the dipstick when taking a reading).  Yeah, we all know you will reuse the pan drain plug crush washer, but it really is best to use a new one, as a used one might leak.  

BMW originally used crushable, fold-over type crush washers, and later, solid ones.  Either is OK.  Early models have shallower oil pans, and you may want to keep the oil level a bit lower than the maximum marking on the dipstick....otherwise the first half-quart or so might disappear too quickly.  That effect is worse with 'cheap' oils.   It is particularly so on the earliest models with round breathers withOUT the breather drain-back hole.  For detailed information, and photos, click on:   oilsketch.htm

HINT:  AVOID bending the left throttle cable when checking the oil level at the dipstick.   Note also that the dipstick reading is taken by removing the dipstick, wiping it off, then inserting it, but NOT screwing it in, before looking at the oil level reading.

If you are also changing the oil filter I suggest you first drain the oil as above; then, put the bike on the SIDE-stand, which tilts the right side up for easier work on the oil canister area. 

Things are more complicated if you have a later model or any with an oil cooler.  There are more items, they have to be installed in the correct order and with the canister depth measured, etc.  I will get into all that in this article. Be sure there are no old O-rings, etc., in the canister before closing it up.

Once the old oil filter is removed and the new one installed in accordance with the depth, etc., and the cover installed, you have an oil chamber area that is empty of oil.   All the oil from your engine's oil pump must pass through that oil chamber (called the filter canister) first, before the engine parts that need lubricating, get any oiling.  You want to fill that chamber with oil, and pressurize the system.  It is not necessary to go overboard on doing this.   QUITE frankly, it perhaps is NOT REALLY necessary to go through the oil filter chamber filling method I outline below...and that BMW wanted you to do.  BUT, I do think it BETTER to fill the chamber (and cooler if you have one) properly, than not to.

IF you changed the filter, ALWAYS hang it to drain well, and then use some large dikes or pliers, and pry (NOT CUT) off the metal ends.   Remove the outer wrapper, and then unroll the filter.  Look for metal or other particles, in every pleat, both sides.  By looking carefully for any particles, all pleats and sides (we hope you have no substantial metal particles of any note), you could probably determine what area of the engine they came from.

The standard method of filling the oil filter chamber is to use the starter motor to crank the engine, without letting the engine start.   Some folks will short out the spark plugs; or, remove them and tie the spark plugs (with caps attached) to the cylinders, perhaps with a sash rod spring to keep the spark plugs in contact with the cylinder metal to protect the ignition parts.   I do not believe either method is really necessary.  I just turn off the gas, empty the carburetor bowls, replace the bowls, and crank the engine.   The battery and starter motor are more than capable of the necessary ~10 seconds of cranking time.  You can then ride to recharge the battery, or connect a trickle charger or Smart Charger.  

This is what I recommend:

 Turn the petcocks off.
 On the center-stand, drain the warm oil from the oil pan.
 If you have a magnetic drain plug, inspect it for particulate matter.  

NOTE:  If you do not have a magnetic drain plug, and want one, and I HIGHLY suggest you use one, you can use 11-41-2-343-498, which is used on the F650.  The threads are a bit shorter, so do not over-tighten this plug.  Use the same gasket/crush ring as previously...but a new one, of course!  Many dealerships and Independent's carry proper magnetic drain plugs, of that number and of others.

Some fine powder, not feelable particles, is OK, on the magnetic center.

Put the bike on the side-stand, and do the filter area work, if that is to be done now.

4.  Some folks like to do a particularly thorough oil change, and drain the cooler.  BMW no longer says the cooler has to be drained.  You will drain it if you are changing the filter, because the hoses, disconnected, simply drip, drip, drip.

5.  If you are draining a cooler, which you WILL BE if you have one, add the following:  unscrew the two 17 mm banjo bolts, let the hoses hang down and let the cooler drain.   You will need FOUR NEW banjo bolt washers.  NOTE:  The Banjo Bolt is a funny looking hollow bolt, 17 mm hex head.  DO
NOT reuse the 4 washers.

6.  Change the filter and associated parts, reinstall the banjo bolts using 4 new washers.  Note that these washers almost always will get a faint metal deformation, and reuse of old ones is a BAD idea.  
****If you are NOT 100% informed about the problems with the -098 large round O-ring, etc., that may be on your model bike, and the shim, ETC....then read the information in this article again.  I mean this!!!...this is NOT an idle recommendation!

7.  Tighten the 17 mm banjo bolts with fresh washers to 13 foot-pounds.  The absolute limit is 14.5 ftlbs.     Be sure to retighten them overnight,  or at least after a few hours.  It is a good idea to position the outer hose away from touching any fairing, where fairing vibration could loosen the banjo bolt.   Tightening the 17 mm banjo bolts to over 14.5 foot-pounds is likely to result in shearing them off, or, cracking them, and it might not show up for awhile.  You can lose all the engine oil.  Do what I say!....

8.  With the petcocks off, carefully remove the carburetor bowls one at a time, inspecting for dirt and water, and that the central pipe and the corner jet are clear, and empty the gasoline...back into the tank, not on the ground!....environmental hazard!   If your Bing CV carburetor bowl gasket is in poor condition, replace it, as a poor gasket can affect the enrichener operation.  Reinstall the bowls, making sure the gasket stays in proper position.
9.  Fill the crankcase with about 1-1/2 liters of fresh oil.

10. Crank the engine until the OIL lamp goes OUT, this will take about 10-15 seconds.   Do NOT confuse the OIL lamp indicator and the GEN lamp indicator.

11. IF you drained the cooler, and your motorcycle has the BMW thermostat cover, you CAN refill the cooler, failure to do so can possibly cause damage, per BMW's old literature, when the thermostat opens with a large high pressure surge into the cooler.   It really is PROBABLY not necessary, as the thermostat SHOULD open slowly.  Because of uncertainties, I prefer to use the special bolt and refill the oil cooler.  The GS models use a hole, not a thermostat, so there is no special procedure for them.

 For the thermostat models, install the special long hex-bolt, 23 mm thread length.  Do NOT use it if it is a very rare wrongly made one that is not 23 but 25 or 30 mm.    The special and proper 23 mm bolt has a smooth heavily rounded tip...a FULL radius tip.  ***Description and photos of the proper and the wrong thermostat/cooler refill bolts are in the HARDWARE article on this site:  Hardware.htm.   Somewhat more detailed information on this refilling bolt is located at item #30 in the following article:   tools.htm

Install this special bolt together with the old washer, finger tight (or, LIGHTLY with 10 mm wrench), in place of the much shorter 10 mm bolt, at the bottom of the thermostat.  Again crank the engine until the OIL lamp goes OUT, this will take a few seconds at most.  Again, don't confuse the lamps.   Install the proper short 10 mm bolt and washer.   If your bike is a GS model without the thermostat, you don't have this procedure, as there is no thermostat, nor need for the special bolt.  Still, you want to crank the engine to fill the oil canister but your oil cooler will fill, or partially, at the same time.

12.  Put the bike on the Center-Stand.  Turn on the petcocks, start the engine, let it run a minute,  looking for leaks.  The oil lamp must not be lit after the engine starts, not even at idle!

13.  Shut off the engine, wait a minute or so, recheck oil level; you will have to add some.  BMW airhead oil levels are checked on the center-stand, or balanced, & the dip stick is NOT screwed down when taking a level reading.  Top up the oil as required.  You may want to keep the oil level just a bit below full.   Do NOT over-tighten the dipstick, it tends to tighten itself with heat/cool cycles.  The early metal dipstick has a metal crush washer & that washer must be there.  The later style black top dipstick has a rubber O-ring in a groove which must be there.   Dipsticks vary in length, and markings, between various years and models of motorcycles; and some are modified for other oil pans.  Information is on this website on various dipsticks.   AVOID bending the left carburetor throttle cable when checking oil level!   

14.  Do not forget to re-torque the cooler hose banjo bolts at the thermostat (or, if GS style, at the plate) after the engine has cooled, preferably the next day.  Do not forget the caution on the outer hose touching the fairing.  If the hose is in contact with the fairing, the banjo bolt CAN loosen.  Recharge the battery.   The torque on the banjos (use a 17 mm socket) is 13 foot-pounds.   USE a torque wrench, do NOT guess. Be sure the hose banjo fitting, etc., do not move when tightening (HOLD it).

15.  Oils of somewhat questionable properties tend to 'burn up' rather quickly, particularly the first 1/3 to 1/2 liter; even more so on the shallower oil pans that tend to have more blowby and oil burning via the carburetors.  It is usually a matter of the additive package, but can also be due to lower grades of crude oil base stock.    Airheads with the smaller volume crankcases, especially pre-1980 (a pan size change was made in 1977), tend to make the situation worse.  Engine condition, in particular the rings, valve guides and style/condition of the breather valve, also have quite an effect on oil usage.  The early style round breather valve is prone to making gobbling noises, and may get chipped or otherwise damaged with age....and there is a drain back hole in the cavity (except earliest models) that is hard to find and it needs to be kept clear.  You can install the later reed valve in place of the round disc.  The round disc, if damaged, can also be duplicated out of printed circuit board material (a type of glass fiber and resin material).  BTW...with the round disc unit, there is an adjustment.  The stiffer spring position (lower groove) is for the R75 engine.  Replacement discs are NLA from BMW, but I have references on where to get them if you do not want to make one, which is a PIA if you have no lathe.     oilsketch.htm  has sketches, photos, etc.

***BMW came out with a factory bulletin in 1975 or so.  The bulletin dealt with increased oil consumption on some models, specifically the R75/6; R90/6, and R90S.  The bulletin said to use a DEcreased amount of oil when changing/filling.  The new amount was to be 1.9 QUARTS.  Obviously the value YOU use depends on which oil pan you have installed, as many have been changed over the years.

16.  It is usually OK to change the filter and any O-rings, at every other oil change. NEVER EVER reuse the -098 white high pressure O-ring!  It is OK to extend the oil drain period, mileage-wise, if you are on a long tour.  Those doing stop and go city commuting, and especially those who do mostly short rides of under 15 miles, and especially in high humidity areas, should change the oil MORE often.  Generally speaking, under average use with non-premium oils, my recommended change is every few months and 3000 miles, whichever comes first. Premium oils usually can go twice that.   SOME premium oils are fine at really depends on how the engine is being used and the base stock and also the quality of the additive package in the oil, and the amount of blowby.

A lot about the health of your engine can be had very easily.  When you change your oil filter, follow this procedure, EVERY TIME:
     a.  Drain the oil filter overnight (hang it to drip)
     b.  Use a sharp knife and slit the outer paper wrap
     c.  Pry the ends off.
     d.  Remove the pleated paper and stretch it out, and look, both sides, in
     e.  If you see some few extremely fine metallic particles, it is probably normal
          wear.  However, if you see any pieces that you can identify with a
          magnifying glass, this is what they mean:
             1.  If dull, flat, gray on one side, it is Babbit metal, from rods and mains.  
                  The other side will be coppery in color.
             2.  Non-magnetic aluminum chunks that look like rough teeny snowballs
                  are from the corner of the main bearing carrier, from a worn top
                   sprocket and chain.  This is far more likely to happen on a PRE-1979.
             3.   If there are rubber bits, or hard plastic, this is almost for sure from the
                   cam chain tensioner.  Tend to be pointy.   Early models had rubber,
                   replacement 'shoes' are plastic.
             4.   If the bits look like brass or bronze, they are from valve guides.
             5.   If there are pieces of WHITE soft rubber, it is from the oil canister
                   large, high pressure, O-ring.

17.  Very roughly from about 1988, and this is not an absolute date, as it was phased into production, and some very late models might still NOT have this:   the canister got a LIP at the outer edge.   This lip was supposed to eliminate the need for the thin (0.011") metal shim....the purpose of which was to keep the canister edge from cutting the large white O-ring.  These so-called rounded-edge canisters may, or may not, exist in your later Airhead.   You still should measure the distance between canister and the outer engine face...see information much later in this you MIGHT need to use a metal shim, ETC.

18.  moved

19.  Deeper than the somewhat shallow original allen head screws are available from your dealer for the three outer cover screws.  They tend to round-out far less.  Do use locking (for instance, star type or waverly) washers.   It is a good idea to use a faint smear of anti-seize compound on the threads and washer...and do NOT over-tighten.  These do NOT have to be tightened very much. JUST moderately SNUG. Tighten in stages, evenly.

20.  Do not use single weight oils, unless you have a problem breaking in the rings on a newly ringed engine.  Do NOT try to break in an engine on full-synthetic oils.  Engines will usually, NOT ALWAYS, break in OK on semi-synthetic oils.   Some folks will use a common cheap car oil the first 50 miles of break-in, then change to a quality oil, ....again, not a full synthetic.  I think this is dangerous to engine life, due to lack of ZDDP.  I have safely used Rotella or Delo diesel oils, the NON-full-synthetic ones.  They have ZDDP in them, and are much easier on the cams and followers as an example.   I haven't looked into the ZDDP content of those oils in some time....if you want to use those oils, I suggest you find out.

21.  The OIL light must NEVER come on ANY time the engine is at idle or above...UNLESS you have a faulty oil sender switch.    Temper that statement with the fact that on some of the bikes a VERY vigorous stop can cause the light to flicker MOMENTARILY...and this is OK...usually.   If the oil light otherwise comes on at idle or above...stop the engine right waiting!!!   The problem is likely the switch...or a sliced 11-42-1-337-098 large white O-ring at the filter canister.  It really takes very little time for low oil pressure to damage your engine.   

NOTE:  the part number of the 11-42-1-337-098 O-ring was, a long time ago, 11-42-1-264-160.    It is 44 mm x 4 mm.

NOTE:  The stock oil pressure switch activates at an oil pressure of approximately 3 to 8 psi.   Generally speaking, even with very hot and thin oil, the oil pressure will not fall under 15 psi.

NOTE:  In a few rare instances, especially with thinner oils in very hot weather and/or with extreme stop and go traffic conditions, the engine, and oil, may heat up enough to cause the oil pressure to drop enough to activate the OIL lamp.  This can be more likely with VERY vigorous braking and worn engine bearings.  

NOTE:    Idling the engine for long periods of time at low rpm, ESPECIALLY with a fully heated up oil/engine, is NOT a good idea.  This WILL greatly reduce the output from the oil pressure relief plunger valve located in the timing chest, and thereby INcrease wear on the timing chain and crankshaft sprocket and the camshaft sprocket.  This is a good reason to not set the idle rpm too low.  I think airheads should NOT be idled under 800 rpm, and probably better at 900-1100.   This also helps with synchronizing the CV carburetors...they are less touchy at 1000.  I use 1025 rpm on my own 1982+ R100 bikes, but 900 on bikes prior to they have a heavy flywheel.  Excessive idle can also increase wear on the camshaft and followers.

22. The oil pressure lamp is there for several purposes:
     #1:  You are soon to be pitched over the bars from a seized engine, and you have already
            damaged your engine.
     #2:  Advance notice that your bank account is going to be drastically affected very shortly.
     #3:  You want to know that the filter chamber and/or cooler is refilled after changing the
            filter; & you you really SHOULD finish that job by adding oil to the sump in the first
     #4:  You are VERY low on oil, and you may have already damaged your engine.
     #5:   Cause you to worry more, and perhaps change that faulty switch, or warning you to
            stop doing 'stoppies' (making extremely abrupt stops). 
     #6:  You did not measure your filter canister depth; and/or, you did not assemble certain
            things properly, such as O-rings, shim (if needed), paper gasket (if needed), ETC., &
            the white high pressure O-ring is either cut/leaking; or, the white O-ring is not sealing
            the canister to the engine wall, & high pressure oil in the canister is going directly to
            the crankcase, patially bypassing the important parts of the engine, giving LOW oil
            pressure in the engine, & likely is injuring that engine.

23.  BMW could have used a sender switch that closed its circuit at perhaps 20 or 30 psi.   However, BMW may have thought that the lamp then coming on in hot riding and braking, or even at normal idle; perhaps with thin oils, and so on,  might be confusing/annoying.    Aftermarket switches are available with a higher set point.  Unconfirmed information given to me is that a switch sender used in water-cooled Volkswagens at their filter, part number 056-919-081E is rated at 1.8 BAR, which is approximately 27 psi.  I do not know if the threads are straight or tapered, so as to fit the airhead engine threads (EARLY airheads used a different thread!).  Note that part number as above but ending in C is rated at 0.3 BAR, and I have no information at this time on part number as above but ending in B.  Information straightening this out will be appreciated.  IMO: use the STOCK BMW MOTORCYCLE oil sender switch.  The BMW switch is about ten bucks...use it!

24. The thermostat seldom fails; unless abused by use of the wrong length special cooler drain bolt.  They have been known, RARELY, to stick.  This does not have any real effect on engine oil flow.  The thermostat is NOT simply an on-off valve.  The valve inside it determines what percentage of oil is routed to the cooler.   The thermostat is specified to begin to open at 80C (176F) and be fully open at 110C (230F).  GS models without the thermostat use a sized hole to control the temperature to the cooler, it seems adequate, although using a lot of rpm with the engine oil itself, at startup, at very low temperatures, MIGHT be hard on the cooler soldered/brazed seams.  The GS cooler is also supposed to be COVERED in really cold weather, to avoid OVERcooling the oil.

25.  The earliest airheads, such as the /5 and /6 series, up to a change in 1976, had a 3 bolt outer cover, but, when that cover is removed, you will see that, inside the engine, was a round metal cap cover, held onto the end of the oil filter canister by a single large bolt that screwed into threads in the center of the central pipe, which was not the same length pipe as the later models, thermostat type or not.  NO inner cap-cover sealing method (no gasket of any type) was used to seal that early inner cap-cover to the metal canister. No gasket or washer was used under the bolt head.   On early airheads, with this metal INNER CAP-COVER,  the OUTER 3 bolt cover MUST have a paper gasket.    NO sealant is used on that paper gasket. None of the problems with the later models with cover O-rings, coolers, and so on, are had with this early simple system.  For this early system,  replace the paper gasket each time the outer cover is removed.  Be very careful not to nick the metal, or the gasket won't seal well.  The original /5 filters were sealed to the metal cap cover and to the far inner end of the canister, via small round black O-rings, that lightly push fit over the central oil tube.   These O-rings were normally replaced at each filter change, and removing the innermost one was done with a bent end of a straightened coat hangar.  Later, these small O-rings were eliminated, in favor of bonded-to-the-filter rubber seals.  At one time filters were available that had the bonded rubber only for the far INNER end, and one small O-ring was still used at the OUTER end of the filter. 
Do NOT confuse these words with the much larger separate O-rings now used, which do NOT grip the central tube.   Note also that modern filters may have bonded rubber at both ends for the early bikes. 

On the later bikes:  An outer medium-sized O-ring, square sectioned, may be used to modestly seal the right end of the filter metal to the outer cover plate.    NOTE that the pipe must be very tight into the engine block itself, and that pipe is longer on the cooler-equipped models.  MANY an early model has been converted to use a cooler.  Information is later.

The O-rings on the cooler-equipped bikes are 34 x 3 mm and 44 x 4 mm.  You don't need this information, since you WILL, if smart, use the BMW parts.

26.  Later models, cooler or not, eliminated the inner metal cap-cover,  including of course, eliminating the large central bolt.  Those with the earlier style inner cap-covers with the large central bolt, are NOT AT ALL concerned with the $2000 O-ring, because there is none!
NOTE:  If you have an early model that has been converted to use the factory style oil cooler and thermostat, these comments regarding metal inner caps and no $2000 O-ring problems are only for reference purposes, as you have essentially nearly the latest production version; that is, the central tube was changed, and there is no inner metal cap cover or bolt, and you have a thermostat cover with two sizes of O-rings, and you use different filter model(s).....and you ARE vulnerable to the $2000 problem.   Note that when the oil cooler is installed on a motorcycle that did not originally come with a cooler, the central pipe is changed, it becomes longer, and sticks proud of the engine case surface by ~3 mm.  Note also that if the bike originally came with the inner cap cover, then the canister itself must be removed and the later type installed at ITS proper 3.0 mm distance from the outer wall of the engine. 

NOTE:   Some few models, like the GS....have the frame somewhat in the way of the outer plate...if that plate was the thermostat type.  BMW uses a NON-thermostat plate for these installations.

27.  After the inner metal cap cover was eliminated, all airheads still used an outer 3 bolt cover, although several types were used.    Use here of the words  ' outer cover'  includes both cooler and non-cooler models, thermostat or not.    These covers had two different sized O-rings, both are needed.  The cover has inner grooves to retain those O-rings.     The smaller one WAS that previously mentioned 34 x 3 mm round O-ring...that is, it was round in early production, 11-42-1-337-097, but it is no longer available, and a square sectioned one is SUPPOSED TO BE a separate part, in the oil filter box.  The factory MIGHT have shipped the bike with a paper gasket at this cover....that is, the paper gasket, when and if used, fits between the 'cover' and the engine block, and BMW drawings usually show that gasket.   That paper gasket should NOT be used, except in rare circumstances.   The factory might have installed a shim at the canister.  That shim is almost always to be used.   That metal shim is 11-42-1-336-895, it is about .010" thick, and its purpose was to prevent the sharp thin edge of the canister from cutting the large -098 O-ring (44 x 4).   The shim was installed in all models by 1979.  It is a MUST for all the non-rolled edge canisters, which is most canisters, certainly all the early ones, perhaps up to at least 1988.    Much more on those items later herein. 

OAK's $2000 O-ring articles were prompted originally by an inquiry from someone who did major damage from using a too thick cover gasket (an aftermarket item), when no gasket at all would have been just fine, and preferable.   What is often not understood properly is that the metal shim is there to protect the large, usually white, HIGH PRESSURE O-ring from being damaged by the sharp edge of the canister, and ALSO to increase pressure on this large O-ring.   That large O-ring is the CRITICAL one, the so-called $2000 O-ring, and its part number is 11-42-1-337-098.  NEVER reuse one of those, and always inspect the new one, never nicking it in the slightest whilst you install it.    Some filters (kits) are sold with those large O-rings. If your filter does not come with the O-ring, GET ONE.    BE SURE to have the proper O-rings, etc., when you are ready to replace an oil filter.  You might even need a fresh metal shim, if yours gets deformed.   I recommend that you stock a few spare white -098 O-rings and shims.  INSPECT the filter kit, etc., at the dealership, when you purchase sure the needed parts are there.

NOTE!!!....The right side open end of the canister is NOT part of the outer engine wall, there is a small space between the outer end of the canister and the inside wall of the engine.  The purpose of the large white O-ring is to seal that space and also to seal the canister to the outer cover. MIND THESE TWO SENTENCES...., RE-READ TWICE!

If this large O-ring does not seal perfectly in one critical area....that distance between canister end and inside the engine block (engine block inside wall), then the VERY high oil pressure inside the canister, which comes
DIRECTLY FROM THE OIL PUMP, can leak/flow back into the oil pan/sump.  You very likely will NOT see tell-tale outside leaks! 

This will reduce oil flow in the engine, and it can be drastically reduced. Due to the very high pressure, a NICK or cut in the large O-ring may change to a nice notch, and allow a lot of oil flow downwards to the oil pan, instead of into the proper areas of the engine.    If a 'cover' paper gasket on the 3 bolt cover is used, its stock thickness of paper gasket MAY be just thick enough to give problems, especially without a metal shim, ...there may well be insufficient pressure on the large O-ring and its sealing may fail.   Obviously the large white O-ring must be in perfect condition.  It is
foolish to not replace it any time the outer cover is removed.   Mind my words here:  that large O-ring tends to flatten over time and use in the engine,
and must not be reused.   The large O-ring needs a certain amount of compression to be fully effective....but not too much.

    In late 1978 the factory began adding the metal shim.  It was then available separately, and the part number is: 11-42-1-336-895.  It is approximately 0.010"-.011" in thickness, THEY VARY SLIGHTLY, OFFICIALLY THEY ARE 0.3 MM... and of diameter to match the outer face of the oil canister. No, it won't slide down into the oil pan! The earliest of these shims was made in such a way that one side had a sharp edge.  If you have one of those, the sharp side goes INwards, and contacts the canister.  
 The shim is installed immediately, that is, it is the NEXT ITEM,  after installing the filter itself.  The purpose of this shim, now packaged with most filter 'kits', is, as noted above, to keep the canister end edge from cutting the critical large white O-ring, part number 11-42-1-337-098; and, to increase the pressure on that O-ring.   The metal shim DOES NOT fit against the 'cover', rather, it fits against the canister.  The filter KITS do not include two shims, only one.

29.  BMW manufactured some very late canisters with an outer lip, that supposedly do not need the metal shim.  The literature is QUITE confusing on this, and it APPEARS it was introduced in late model RS bikes; perhaps in 1988; NOT trust that you have a lipped canister, so, LOOK!   In any must be very careful about not using the shim.  In fact, in some rare instances, with canister depth being too far out of tolerance (read on, later herein), I have installed two shims, and no paper gasket.  The important thing is that the -098 O-ring is squeezed well, yet not so much that one cannot get the outer cover fully seated onto the engine..... not too much pressure....lest the O-ring be damaged, etc.  A very complete analysis of the proper dimensions follows later in this article (see Oak's August 2004 AIRMAIL article for a different way of examining the clearances).   If you are not sure about the edge of the canister, and the dimension of the canister to the outer surface allows (read later herein), then by all means use the metal is compatible with rolled edge canisters, if the dimensions allow.    Even if you have a late lipped canister, you may need the shim!

  NOTE that BMW claimed, in a Service Information Bulletin 11-021-82 (2050) that sometime during the 1982 production year the canister end was changed to a flat/lip....I have NEVER seen a early 1980's rolled edge (flat/lipped) canister....but, BMW did make a machining difference on the lip....that is not really what they mean, however.  The confusion comes because the lipped canister WAS introduced in EUROPE in 1982.   NO MATTER, it is the dimensions that are critical, and the metal shim is used in every instance of the early 1980's canisters that I have ever seen.  A real 'lipped' canister should be easy to see visually.

The 11-11-1-338-203 lipped canister was the last version of the oil filter canister.   I never bothered to measure any, but Anton Largiader did, and reported thusly:

137.60 mm deep
51.85 mm lip outside diameter (noting that the case is 52.0 mm)
45.50 mm lip inside diameter (cover lip is 45.0 mm)
49.85 mm tube outside diameter

Earlier canisters may vary in length, at least somewhat, compared to the -203.  Anton reported a 1977 was 138.2 mm, with the block machined to 142. mm.

NOTE:  the BMW factory specification for the canister to outer wall depth, on ALL models with the later type canister (not the single bolt type) is MINimum 0.122"; MAXimum 0.1496".   Many are found outside this range, and this article discusses how to deal with that.

30.   Airheads with coolers have either the outer 3 bolt plain cover replaced by a thermostatic controlled cover (Nerdy information:  The bypass hole in the THERMOSTAT cover is ~0.316" diameter.), or in the case of later GS models, with a restricted orifices outer cover. On the GS models with oil cooler and the non-thermostat cover, there is a factory bulletin on the early covers.     The bulletin says to inspect the small hole in that cover, and if 2.0 mm, to drill it to 5/32" (that is 4 mm for the math challenged).  That is the bypass port hole, the function of which is to allow SOME oil to flow, even if cold.  Increasing the hole size reduces the amount of oil trying to pass through the cooler. Speculation is that with the original smaller hole, some coolers ruptured with starts in quite cold weather from the VERY high oil pressure when the oil is very cold.   

The GS cover does not have a thermostat.  It uses that above specific internal hole size to ALWAYS allow some oil to flow, and as the oil thins from heating up, more oil flows.  As noted above, the EARLY GS covers had a too-small hole, and it needs drilling....for the reasons outlined.  The GS radiator must be COVERED in quite cold weather to avoid OVER-cooling the oil.  The advantage of the GS plate is that it is simple, and takes up less room in the canister area as  the frame on the GS models is high, and the thermostat unit would NOT FIT those frames.  Take a look at a GS sometime. 

The oil cooler setup is a bypass system.  Only part of the oil flow into and through the engine goes through the cooler.   On the thermostat-controlled system, the cooler gets oil flow when the bike is at speed; that is, when some goodly load is on the engine. Yes, the thermostat probably does not operate in typical busy traffic riding, as BMW engines cool rather well.   A cooler is a VERY good idea for a sidecar bike, or a bike ridden in hot weather, especially at speed.   You can tell if the cooler thermostat is working by riding at speed for a few minutes after engine warmup....the cooler will get hot. The thermostat unit should not be disabled permanently, that is, there is no reason to keep the 23 mm bolt installed, and I recommend against that, it can cause OVERcooling of the oil, a BAD thing.   
The only purpose of the special 23 mm bolt is to refill the cooler radiator if it has drained.   It WILL drain, when you remove the cover you will unfasten the banjo bolts (stock the aluminum gasket washers in modest need 4 each time).   For some reason, BMW sells filter kits withOUT those aluminum banjo bolt washers....maybe they will include them in the future. The REASON for filling the radiator during an oil filter change, which requires that 23 mm bolt on thermostat models, is that if the engine is started when quite cold is not specified...nor is the oil grade.....then the HUGE oil pump pulse output upon starting MIGHT rupture the oil cooler if the cooler was empty.   For anything but really very cold conditions, refilling the radiator is probably not necessary....but many of us do it anyway....heck, it MIGHT protect the cooler.  Frankly, I do the cooler refilling, but some say it is not necessary.  I am wishy-washy on this.
A few of the supposedly and proper 23 mm special bolts were made overly sure yours is 23 mm, and be sure the tip is a FULL ROUNDED RADIUS; to see a photo and description of the correct and the wrong bolt, see:  CLICK for the hardware article
      OR;    CLICK for the TOOLS article  and scan with your mouse to nearly the end of the article.

31.  The center pipe in the oil canister area has been known to loosen.  Be sure it is very tight.  If it is loose, perhaps by 1/8th turn or more, remove it, clean male and female threads with a good solvent, and use RED Loctite sparingly, before replacing, tightly.  Use an appropriate sized tool, do not bugger up the right end.   Some may go so far as to have a special tool made, a mandrel like affair.  A very thick, well fitting, very broad, parallel tip screwdriver CAN be used.  Grind such a screwdriver or make a tool for yourself.   If you do NOT use the proper tool, you will cause BURRS in the pipe end metal, that must be removed, or the pipe will not fit easily into the cover plate, and could even cause too much leaking there.  NOTE that the cooler models are supposed to have the pipe installed such that the pipe is sticking out, outward of the engine pad surface, by 3.0 +- .4 mm. It really is not overly critical, the pipe must fit inside the cover some, when bolted up..  There are two basic types of center pipes.  The short stubby pipe used with the single-piece filter (and old cap cover models), and the longer pipe used with the cooler and later models.   NOTE that if you are installing a center pipe, and at the 3.0 mm distance proud of the engine it is loose, then use Loctite Red, and hold the pipe centered by installing the outer cover overnight.

***Do NOT confuse that 3 mm pipe distance, PROUD of the engine casting....with the CANISTER depth of 3 mm. 

Note:  When trying to remove a center pipe, considerable force may be necessary, and I HIGHLY recommend a custom-made mandrel.  Some have used a thick very large screwdriver blade, but if it slips, you will bugger up or otherwise damage the center pipe outer end, and then have some fun in figuring out how to remove the pipe.  This is especially so if Loctite was used at the inner threads where the pipe screws into the engine, because you have no good way of heating that area hot enough, and might damage the ball and spring off to one side anyway.  A way to remove the center pipe without welding washers or nuts to it, is to insert a proper size of Screw Extractor; there are several types of those available at almost any autosupply store.  Here is a photo of what happens to a central pipe when not using a mandrel, and a badly fitting screwdrivers, and the type of screw extractor that works OK.  Be careful, they are brittle!....keep it squarely centered, etc.
This tool is also sold as an EZ-Out, Easy-out, etc.


32.  The Large High Pressure O-ring 11-42-1-337-098 is a nominal 44 mm outside diameter and 4.0 mm thickness.  The metal shim is nominally ~0.3 mm thick (~0.012"), with some small variances in thickness being seen, down to ~0.010".  Most of the metal shims seem to measure .011" give or take a bit. The paper gasket is 0.5 mm thick and is 11-42-1-338-600.  There was an earlier number.    These dimensions are NOT important, unless you are using the method described by OAK in the August 2004 issue of Airmail.  In MY treatment, herein, you need not calculate anything, if things fall within the tolerances I show here.

33.  Once in awhile I am asked about what temperature the oil is supposed to be at. Now and then come questions about the use of deeper oil pans and aftermarket cooling-tube inserts between pan and engine.  Questions also arise about the effectiveness of the oil cooler (the GS type and the thermostat type are about the same in cooling effect, except the GS type can OVERCOOL in colder weather, without a COVER).

There are no exact numbers.  Your Airhead is designed to operate OK over a wide range of atmospheric temperatures, road speeds, idle resting time, and oil temperatures.   BMW has published very little in the way of what oil temperatures are supposed to be.   One figure that HAS been published by BMW is what an accurate dipstick type of temperature gauge should read from normal riding.  The stated normal figure is 80C (~176F).  They do not specify the actual riding conditions nor atmospheric temperature.   The faster you ride, the higher the oil temperature is going to be as the engine is producing a lot more heat, and the increased air velocity across the engine is not going to cool the oil as fast as it heats up, from that increasingly higher power output.  The heat is produced at roughly 3 times the rate of cooling, per speed amount.    You NEED at least 180F at some moderately large areas in the oiling system that the oil passes over or through, in order to adequately 'burn off' moisture that accumulates in the oil.    Your Airhead has some VERY hot places, far beyond what a dipstick thermometer might measure.  These places are around the exhaust valve guide, the cylinder head and cylinder in general, and some other associated places. BMW also has published nominal values for when the thermostat (on those models so equipped) should start to open, and when it is fully open.    I have published that information on this website.  In general, the cooler can be counted-upon to reduce maximum oil temperatures ~15. That does not seem to be much, but it IS significant!   Petroleum-based oils are generally going to be OK up to 230F+-, and as temperature rises above that, the oil will increasingly begin to deteriorate.  Someplace north of 275F, the oil is VERY quickly going bad.   Semi-synthetic oils like Golden Spectro 4 20W50, which is one of the oils I recommend for our Airheads, does better, with its premium oil base and quality additives.   Some synthetics, including the full-syn GS, will do even better...but are NOT required.   Keep in mind that some of the oil gets exceptionally HOT near the exhaust valve area, etc.....but for brief periods of time, as the oil is constantly circulating (but not in large volumes at the valve area), thus, deterioration of the oil to the point it must be changed, happens rather slowly.

34.  With regards to the later models (NO inner metal single bolt cap-cover), BMW has goofed on occasion in the installation of the canister.   Sometimes it is set too far in, and in VERY RARE instances, it is set too far out.  Some folks think it can move, over time, with engine heating...I've seen that once,, measuring your canister more than once over the years is not a bad idea!   The depth of the end of the canister to the outer cover mounting pad surface is fairly critical, as the O-ring must seal both the canister to the outer cover, and the canister to the engine casting wall, preventing oil from escaping the cover to the outside and in particular from escaping the canister area directly down to the oil pan.  The actual specification for the distance from the end of the oil filter canister to the OUTER face of the engine casting is 3.0 mm (0.118").     You can use a T style depth gauge, or the end of a vernier caliper.  Use these squarely and accurately. 

      If the distance is exactly 3.0 mm (0.118"), you can use the paper gasket, or not.  At
      3.0 mm and no paper gasket in use, there will be a slight over-pressuring of the large
      O-ring, but probably this is OK.

      If this distance is over 3.0 mm (0.118")  you must NOT use the paper gasket!!  You MIGHT
      have to double up on shims too!   The large O-ring MUST be under a goodly pressure!
      If this distance is over 3.2 mm (0.126"), use of a metal shim(s) is mandatory, even if you
      have the very last production version of the canister with a lip on the end.  If your depth
      is much over 3.6 mm, you may have to consider using two or more shims....some at
      OVER 4 mm HAVE been reported.    In this instance, refer to the August 2004  OR
      January 2008 articles for calculations; or, just calculate it from known distances here.

      Even the latest rounded lip canisters must have the distance measured, and shims used
      if needed.  If your depth is 4.3, you may want 3 or 4 shims, if 4.5 you want 4 or 5...these
      figures are for NO outer paper gasket.

      Under NO circumstances is a thicker than factory stock paper gasket, or doubling up of
      a paper gasket allowable, UNLESS you have a real, known, measurable reason.  ONE
      reason might be that the canister is not set in far enough and you cannot use the needed
      shim and also need to have the cover fully home to the engine. 

      In a few RARE instances the canister, a press-fit into the engine, has reportedly moved
      deeper into the engine over time, and the measurement has changed.  That is what
      happened to the ONE I saw.   I RECOMMEND that you check your canister depth more
      than once over your time of ownership, keeping notes on the measurement depth. 

     NOTE:  Use of a paper cover gasket, where one is not needed, can mask some types of
                  large O-ring leaks...THUS, it is NOT a good idea to use a paper gasket
if not
                  needed!...and by measuring, you will know!  As a general rule, paper gaskets are
                  not needed, not used, not wanted on any model, EXCEPT that this does not apply
                  to models without coolers that HAVE the internal cap-cover with the single large
                  bolt...these MUST have a paper gasket.

      A few fairly rare situations, supposedly on some R45/R65 models, but has been reported
      on some other models, were found with the canister depth set insufficiently.  The depth
      was UNDER 3.0 mm.  One MUST use the outer paper gasket to avoid excessively
      crushing & damaging the shim & O-ring.  In every instance of this I have heard about, 3 of
      them, the outer cover would not draw up 100% to the engine casting without a gasket.
      When the large O-ring is removed from the engine after the motorcycle has been driven
      a number of times, it will may show evidence of being deformed, that is, flattened. That
      IS NORMALY OK.   
ALWAYS replace a used large O-ring.

      Seriously deformed shims should also be replaced.    

      The order of installation of parts is ALWAYS:  Filter, shim (1 or more usually), cover with
       the two O-rings, RARELY a paper gasket on cover.

      The 11-42-1-250-284 paper gaskets (now 11-42-1-338-600) vary somewhat.   Brand-new
       they measure ~0.02" (0.51 mm)-0.022" (0.559 mm); possibly some are SLIGHTLY outside
       this range.  An APPROXIMATE size when compressed is 0.018" (0.457 mm).

EXTERNAL oil filter conversions:

This has been done, & a 'kit' was sold commercially by Suburban Machinery. There was a major article in Airmail in November 1997 by OAK on that specific conversion, his misgivings, the company's reply. There are probably some Airheads around still running those external filters. That type had hoses from the left side oil filter cover plate area, to a remote mounted spin-on filter. A conversion has also been done by individuals in somewhat similar ways, not from Suburban Machinery. I recommend you do not install a Suburban Machinery setup.

The only other commercial type I know of is this one:
That one is engineered nicely. It is also expensive, plus shipping I imagine, plus some more things you will need.

For the Motoren-Israel, it is a matter of money, complexity added, and whatever you may think of how your cooler connects, ETC.  The link, above, will give you all the information you need to evaluate before purchase (except anecdotal reports, which you can probably find on the Internet easily).

I had a R100RT sidecar rig, with the sidecar on the right side, as is normal in the USA. I left the oil filter and cooler setup dead-stock; EXCEPT for adding the metal shim and deleting the paper gasket, as was proper for my canister's actual depth measurement. Mine was not changed to the GS type plate was the stock thermostat plate type, which works better than the GS style of no-thermostat. IMO. With the proper tools such as a ball-headed T Allen Wrench, and a 1/4" hole in the fairing which is unnoticeable, I had no problem laying on my back and changing oil filters. I had no leaks, no oiling failures, and a lot of miles, some on forest service rough roads. Nothing hanging.   It was a bit more effort to change the oil filter, but not all that much. Unless you are physically handicapped, or have a very specific access reason, I cannot recommend either of the two types of conversions.

If money is no matter, the Motoren-Israel modification, done according to their instructions, should work OK. It will be a fair amount of effort and cost to gain the extra liter of oil and the 'convenience' of the screw-on filter.

Canister and Filter mania:

BMW, over some time, has eliminated filters, and my guess is that BMW probably will eventually sell only THREE filters, one for the old short pipe non-cooler models; and two different length hinged filters for the cooler (longer filter) and non-cooler filter.   IN MY opinion, the hinged filters are best.  I believe them to be stronger and less likely to exhibit a VERY RARE situation, a crushed filter. I suspect that filters eventually will be only available as kits, with extra parts, so the kits will be universal in use.  I also think that eventually BMW will only sell hinged filters.

The canister part numbers are confusing.....and for you anal types, here is some information I am not 100% sure of. The old books show that the canister for the oil cooler model was 11-11-1-263-343, which obviously must be a non-lipped type.   In the early 1980's, the microfiche shows that the canister for the oil cooler models is 11-1-1-337-292.  It might be the lipped canister, but the price book sent you back to the -343 number. In the late 1980's, the microfiche for ONLY the RS model!!....shows an erroneous (?) number for that canister. No microfiche before or after shows that part number, except as the central tube.  The parts price book shows it vastly cheaper.  In 1990, the microfiche shows ALL cooler models using 11-11-1-338-203.  If you go back and now look up the part for the earlier models, it shows this version.   AFAIK, the -203 is the latest, lipped, canister.  Now that you know all this, it makes absolutely no difference, as you won't be changing your canister!  Well, you COULD, but, why would you REALLY want to deal with what THAT entails?

Quite a few manufacturer's make filters that will fit our airheads.  At one time I obtained filters from Purolator, Fram, BMW dealer, and one other manufacturer.   ALL were boxed with information stating that they were for a BMW R-xxx bike.    I did not like what I saw on a few, and I went so far as to send OAK some new samples for his eyeballing.  Both of us felt that pending laboratory tests which we never did, we would stay with the dealer supplied official part.

Purolator:  had 41 paper pleats, paper is of fine grade, proven quality, and the void space between the pleats was maximized. The pleats went deeper, the I.D. size well selected.   From end to end on the I.D., the holes in the grating surrounding the center tube existed.   The pleats were somewhat spread out, unevenly.  The flow rate is proven acceptable.

Fram:  35 paper pleats.  Paper is coarse, lessened void space, not as deep, so square area is less, I.D. is larger that the OK Purolator.  ****From end to end on the I.D., the holes in the grating surrounding the center tube go only about 2/3 of the way, and the remaining area is closed off, solidly.  This reduces the flow rate. The pleats are spread out more evenly than the Purolator, a minor plus factor.  The paper quality is questionable, seems fuzzy, and it MIGHT be decayed by the oil.   Flow rate unknown.   Oak recommended against this filter.

NOTE:  filters may available in bulk, in kits with O-rings, shim and gasket, etc.  Note that I consider replacement of the large white O-ring a MUST if the cover is removed.  Be 100.00% sure that any -098 large white O-ring you install is absolutely perfect, without the slightest nick or cut, etc. Once the metal shim deforms much, it must also be replaced.

If a filter should collapse, due to faulty manufacturing...perhaps a lousy central metal tube in the filter itself?...or maybe excessive end pressure in installing (??).....the canister bypass valve hopes...allow engine oiling.  Have been at least TWO reports of filter failures ruining engines.  I suggest using ONLY BMW filters, or the Purolator.  I am sorry to say that FRAM filters...including their car filters...seems to be of questionable quality these days.   I think the hinged filters are stronger as I have noted, above... certainly easier to use. also sells filters, that seem to be not only cheaper than BMW sold ones, but I have never heard of a problem with them.

NOTE that the Mahle filters are also of good quality, Mahle made filters for BMW.

There are quite a few part numbers for the BMW-sold filters.  Some of the earliest filter part numbers are still seen now and then on someone's shelf. 

After someone visits a 'knowledgeable' dealership it is not rare to find out that he/she has purchased the wrong filter for their motorcycle.  

Filters used with coolers are the longer filters.

11-42-1-253-817:   This filter is for NON-cooler airheads, it is rigid, and short.  Used on /5  and later models. It is replaced by 11-42-1-253-919, which in turn is replaced by 11-42-1-337-198. This is a short filter, around 119mm long.   You will be pleased to find out that the BMW Parts CD says it is replaced by the -572 filter; but it is really the -570 which is the short HINGED filter (same as Mahle OX37).  You will also probably not like to hear that the -198 will be seen in some literature to cross to the -575 filter, which is also the 11-42-9-062-495 filter.  KONFUZED??...see below for the -198.  NOTE that the original type of filter was the Purolator PL-16 and also the Mahle OX-35 was used.   From BMW, the straight non-hinged filter is now obsolete.

11-42-1-335-385:    This filter is 'listed' for 1979 and later RS/RT models with a cooler.  It is rigid, and long.  It is obsolete. Confusingly, some listings may not tell you that it is really for /7 and later, but NOT the R65, and NOT the R80GS, R80ST, R80RT, R100GS, and R100PD.   This is all nonsense.   My Parts CD says it is replaced by the -575 filter.

11-42-1-337-198:    This filter is for non-cooler airheads, it is rigid (one piece, NOT hinged), ~119 mm long, comes with 2 square O-rings (may be seen originally as having rubber sleeves at both ends), and is OK to use to replace the 11-42-1-253-817, but this -198 is replaced, in turn, with 11-42-337-572; really -570 (hinged, with rubber sleeves at both ends).   Are you confused yet, by the -817 short filter being replaced by a long filter? Add to the confusion and see the -572 model.  Add even more confusion: find out that the CD says the -919 filter and a -061 filter were in here somehow along the way.  Add more confusion, some literature will show the -198 being a -575!   However, the more proper literature will show the -198 as being replaced by the 11-42-9-062-464.  The -198 filter is about 119 mm long.  It had rubber bonded at BOTH ends.    It is supposedly for 1969 to 1991 models; but obviously you can't use this non-hinged filter on many models as you simply can't install it....such as the RT.  This filter is called the 11-42-9-062-464 in some literature.  Forget about these filters. 

11-42-1-337-575 (also used in kit 11-00-9-056-146):    This filter, which MAY be marked OX36 (Mahle), is for use with the cooler equipped airheads, it is the LONGER &  HINGED (two piece joined) filter as opposed to the -570, see next paragraph.  It is about 134 mm compressed in length, about 139 mm when not so compressed, and comes with 1 square O-ring loose in the box. It has a rubber 'tube' or 'sleeve' bonded at ONE end.  THAT BONDED RUBBER END IS INSTALLED INWARDS.  It supposedly has the same usage as the -385; and also it will replace the -385. Use it for the cooler equipped models from 1976 onwards.   Another number is 11-42-9-062-495, and you might even find BOTH these numbers on a filter box (-575 and -495).   This -575 filter, whether you purchase it in a filter change KIT (11-00-9-056-146), or by itself, is the one for the cooler-equipped Airheads.  The KIT contains the filter in a separate box, the square O-ring (that is, or should be, in any 11-42-1-337-575 filter box), a paper gasket (for use WHEN needed), a drain plug washer-gasket,..........but NOT the 4 washer-gaskets for the banjo bolts, and YOU WILL NEED THEM.  Note carefully:   The filter INNERmost end has a bonded rubber tube/sleeve.   The OUTER end of the filter has NO rubber tube nor sleeve, nor is there a bonded O-ring of any type.  The necessary square rubber O-ring is supposed to be supplied in the oil filter box.   This O-ring is 34 x 3 mm.  This is NOT the larger 44 mm x 4 ROUND WHITE HIGH PRESSURE SEALING rubber O-ring that is or should be loose in the KIT box.   That white O-ring is 11-42-1-337-098.  

 NOTE:  Purolator made a PL-17 filter, and it is a good one; as is the Mahle OX36.

11-42-1-337-570 (also used in kit 11-00-9-056-145):    This filter is for non-cooler airheads, it is the SHORTER hinged type, comes with 2 square O-rings, and is OK to use to replace the 11-42-1-337-198.  It may be marked OX37, and might measure about 127-1/2 mm long...perhaps 119 mm compressed. It is really the hinged version of the -572, supposedly OK for same usage as -385, plus the R65. OK for most 1976 to 1992 models.  NOTE that this filter is available in a kit, the filter now has bonded rubber ends (BOTH ends), and the kit has the -098 high pressure white O-ring, paper gasket, drain plug washer, and the flat metal shim.  The kit is 11-009-9-056-145.  

11-42-1-337-572:    This filter is for non-cooler airheads, it is the original single piece filter, but it has bonded rubber at both ends.  

OX35:  the short, not for cooler, filter.

11-00-9-056-146:   This is a filter KIT.  It contains the longer hinged -575 filter (for the cooler equipped models, and this filter is hinged) and ONE -098 O-ring, one paper gasket, one drain plug washer, two small metal seal rings, and does NOT have the 4 banjo bolt washers.  This kit also contains one of the large metal shims, 11-42-336-895.    This is probably the filter kit to actually purchase for the cooler equipped bikes, and then get some more of the banjo sealing rings.  I suggest purchasing separately a few -098 O-rings and for SURE a dozen at least of the banjo bolt washers.   Don't use the paper gasket, nor other items, unless needed, but the kit does have that white -098 O-ring that you MUST replace each time.

11-00-9-056-145:   Similar to above, but has the -570 filter.  See 11-42-1-337-570, above, for further description.  This kit is for NON-cooler, has the shorter hinged filter...and that filter has bonded rubber at both end, so there is NO square sectioned rubber O-ring.

So...what do you REALLY do about the filters?  Your dealer PROBABLY has the correct filter number, which they can determine from year, model, and if you have a cooler or not.   BE SURE to get all the parts YOUR bike requires for each filter change. Do NOT depend on UNknowledgeable parts people at the dealership!

The filter part number,  if you are lucky, will remain the same number for a long time.  You probably have a choice of a hinged filter or straight filter...and the hinged filter can make life easier, IF your airhead needs it, some surely do.  I think them stronger too.   Some folks have been known to drill an almost unnoticeable small hole in a RT fairing, to allow easier access to one of the outer cover Allen bolts.  The hinged filter WILL allow you to place the filter into the canister without removing the engine, exhaust pipe (did you know your right exhaust header pipe may have a hidden, inside towards the engine flattened area?), or crash bar.   The angle and position of the hinge is critical to slipping the filter into the canister, without crushing or otherwise deforming the filter.  You may need to experiment, then write down the exact angle, hinge position, etc.   Try to understand the description of the various methods of use of filter, shims, gasket, O-rings. All those filter numbers are not available.  In fact, only a few are available.   This makes it somewhat easier to find a number that is correct for your airhead.    Understand that your dealer may or may not use the parts CD/ETK/Computer to find the latest part number.  Be sure you give the dealer the correct information on your airhead...year, model, with or without cooler.

NOTE:  The factory RIGHT SIDE  exhaust pipe may have a flattened or dimple type area on it, to more easily enable the filter removal and replacement.  I have seen folks try to install the left pipe on the right side.

You should not be overly confused, after all, you NOW understand just what goes inside that canister and cover...right???

nerdy:  the metal shim is 11-42-1-336-895.    51.9 x 45, 3X0, 3mm. The copper washer that is on the bottom of the thermostat is 07-11-9-963-034.  It is in the cooler KIT -146, but you won't need to replace it. It is specified as DT RGA 6.5 x 9.5, and maybe A6 5 x 9, Cu.  Use it if you want to, but always use it on the 23 mm special filling bolt.  The -300 aluminum gasket-washer is 07-11-9-963-010.  Have also seen -301, and they are interchangeable.  This washer is 18 x 22 mm.

Amendments, to try to clear up some details:

#1:  The square O-ring used on Cooler-equipped bikes was originally not square, rather it was round, and was 11-42-1-337-097; that is obsolete.  The square type does not...or, rather, did not, have a part number. It may well STILL not have a part number.  It is normally located in the -575 filter's own box.  The -575 filter does not have bonded rubber at the right (outer) end.  That was continued when BMW introduced the filter KITS.  The square O-ring was then IN the filter box, which was inside the KIT box.   However, that square O-ring is NOT in the -570 box, since that is the NON-cooler filter, and that square O-ring is not needed, as the -570 filter has bonded rubber at both ends.

The cooler type of outside cover plate has two threaded holes for the hoses/banjo nuts.  The cover was made in TWO styles, one had a thermostat.  The GS bikes had a NO-thermostat cover. Both of these COOLER types of covers require the square O-ring, which CAME in the -575 filter's box, at one end of that small box.  That filter had rubber bonded at ONE end ONLY.  That end went into the canister first.  When assembling the area, first went in the rubber end of the filter (the other end, remember, has NO rubber bonded), then came the shim(s), then came the cover with the square O-ring and the WHITE -098 O-ring.   A paper gasket is only to be used when necessary, see much earlier in this article. The purpose of the square O-ring (on the cooler-equipped models); or the bonded outer end on the non-cooler models, is simply to provide a LIGHT sealing to the COVER.   The oil pressure is low at the junction.   The large WHITE -098 O-ring, on the other hand....has HIGH pressure, ....& is a critical part.    It is very important that the proper setup be used as far as shim (1 or more if/as needed), paper gasket (if needed), and -098 O-ring.  

#2:  The NON-cooler covers have NO threaded ports for the two banjo bolts.  BUT....I have seen thermostat covers and also GS style covers that had the two ports, plugged, and the bike's cooler removed. Use the -575 with the black square O-ring.

#3: There is a oil pressure bypass valve located at the innermost end of the oil filter metal canister.  The purpose of this spring-loaded ball-check valve device is to allow oil, unfiltered, to pass into the engine from the pump and canister, if the filter somehow is blocked from oil flow.   This ball-check valve has VERY rarely come loose, and you find parts in the canister area.  Somewhat more often, but still quite rarely, the spring has broken, and bits of it gets into the oiling system....bad news, as considerable damage is possible.  If you have to replace the valve or otherwise repair it, clean the threads with a good evaporating spray solvent, and then apply BLUE (medium strength) Loctite or equivalent, in a SMALL AMOUNT to the threads.   DO NOT get any on the ball and where it seats.  There is no specification on how deep to install the slotted holding part, so you will have to just estimate NOT screw it in way too far, you will change pressure characteristics.   This caution paragraph is repeated elsewhere's in this website, and you can get a better idea of the oiling system by going to:   oilsketch.htm

A RARE event, is an engine with the front main bearing having rotated, which cuts off oil to the rocker arms, & lowers oil pressure.  You will usually find a steel pin, of about 4 mm diameter, about 11 mm long, in the oil pan.  It may, or may not, be on the magnetic drain plug (if you have one).  While the main bearing is a press-fit, if the pin, which is supposed to be pressed-in and staked, comes out (big oil pressure is there, helping to push out the pin), then the bearing MIGHT rotate.  The pin is 11-11-1-253-184.   This is a SERIOUS event, and requires the entire front of the engine to be disassembled.
I recommend you inspect the oil during its draining, be sure there is no such pin.

#5:  Anton has good illustrated information of the oil filter canister setups (some) on his website:
Anton also has an excellent illustrated article, about canister depths and shimming, etc.  You may find it useful to better picture in your mind what is going on.

#6:  BMW provides filters and filter kits, in which there may well be EXTRA parts that you will NOT be using on YOUR bike!!


11-12-2001:  clarity, adding some explanations in greater depth. 
12-16-2001:  remove e-mail address; correct Purolator spelling. 
to 02-12-2003:  minor cleanup, typos, hints, nothing substantial.
03-23-2002:  #4 edited; add thermostat specifications to #10; add specification on pipe
                    distance to lower series #7;  size of the 098 O-ring in lower series #3; add official
                    tolerance to lower series #8; add note on SI to lower series #5; add longer filters
                    for coolers note to Filter-Mania.
04-18-2003:  add .htm title; clarify a number of details.
04-29-2003:  re-number items to eliminate confusion of lower and upper section numbers,
                    expand on the GS type non-thermostated cover; last numbered item is #32.
05/26/2003:  minor updating includes red notes, consolidation of filter types.  Add hyperlinks.
06/12/2003:  Add NOTE in BLUE  about the filter lengths
07/26/2003:  add note on F650 magnetic drain plug to #3
09/05/2003:  clarity & emphasis various places, clarify filter numbers, etc. Many changes.
09/21/2003:  minor clarifications
10/08/2003:  Add -145 filter kit information
03/21/2004:  Clarifications...especially in #27, but in many other places as well.
05/16/2004:  Expand information on -145 filter kit, add a cross-reference to the -570 filter.
08/02/2004:  Update entire article.... mostly simple clarifications, and also adding references
                    to Oak's August 2004 AIRMAIL article.
08/29/2004:  Clarifications, minor, on kit contents.  Add the comments from the Airlist
02/15/2005:  Clarify the canister depths, and more information on filters.
05/17/2005:  Add to #16
07/20/2005:  Clarify details on the GS type cover, versus thermostatic cover, extensively
12/06/2005:  Clarifications, mostly on the paper gasket
03/16/2006:  Edit number #11, #13, #14, #15, #17. Minor editing elsewhere's for clarity
06/07/2007:  Read entire article, add emphasis where needed, clarify wording.  NO substantive
06/18/2007:  Clarify article by re-arranging and adding an Amendment, and numbering for 2
01/01/2008:  Revise #24
02/09/2008:  Canister dimensions
06/25/2008:  Revise #25 for clarity; minor editing, mostly not much further than item 27
08/17/2008:  Edit to clear up possibly confusing OX numbers on filters
08/27/2008:  Slight editing for clarity and add hyperlink to Anton's filter/canister article
09/24/2009:  Update for links to hardware article which has photo now and description of the
                    correct and incorrect thermostat special bolt.
06/16/2010:  add #33, and number the part just following as #34
02/24/2011:  was 52A
05/20/2012:  Add information on External Oil Filter adaptations
08/29/2012:  slight update to #20
12/02/2013:  Go over entire article.  Simplify some areas.  Add more part numbers.  Reduce
                    some colors.  Re-do most of the Amendments, eliminating a LIST conversation,
                    as it was superfluous with the other changes and added information.  Rather a
                    large number of changes.
08/02/2014:  Add note to #15.
09/24/2014:  Go over article, at a first try to make it more usable on smaller screens.
11/10/2014:  Add another hyperlink to Anton's articles.

Copyright, 2014, R. Fleischer

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