© Copyright, 2016, R. Fleischer
Read http://bmwmotorcycletech.info/torquespecs&problems.htm if you have not previously, before using this article.
Torque values between systems of measurement:
Foot pounds is same as pound-feet; ounce-inches is same as inch-ounces, etc.
Nm x 0.7378 = foot-pounds
Foot-pounds x 1.356 = Nm
Mkp x 7.23 = foot-pounds
Inch-ounces = 141.6 x Nm
1 Ncm is 1.416 inch-ounce
Mkp x 9.81 = Nm
Foot-pounds x 192 = inch-ounces
ONE inch-pound is the same as 1.1525 CmKg, or 0.1129 Nm
ONE Ncm is 0.0885 inch-pound.
Bolt head sizes ---- Caution!
BMW is shipping parts that are NO LONGER cadmium plated due to European environmental rules. These non-plated parts tend to RUST! These parts are chemically treated in a different way now, & nearly always OK at the original specified torque as used when they were cadmium plated, assuming the original specs used are in Nm. Unfortunately, there is no information on any of this, NOR any values to use if the parts are removed and then reinstalled, which DOES have an effect, sometimes a goodly one, on repeated fastening torque values. Until this is straightened-out (perhaps never), I suggest you use a faint trace of antiseize compound (where appropriate ONLY) and reinstall at original torque values. Try to obtain old original parts ...in most instances (?) the part numbers are the same, & the dealership might have the cadmium plated ones under the SAME part number and even in the SAME box ...SO ASK.
Never-ever use any antiseize product at wheel bolts, nuts, cone fittings, etc., that hold the REAR wheel to the rear drive. This means the Monolever and Paralever bikes!!
BMW ...Clymers ...Haynes ...ETC.
Literature errors for torque values when listed in foot pounds ...(BMW original errors are often carried forward into Clymers & Haynes books):
BMW of North America published a Service Bulletin, Volume II, NO. 23, Dated 3/82. I will quote some from that bulletin: "May we advise you that from now on, any published BMW conversions found in brackets immediately behind the millimeter figures in all service literature (riders manuals, shop manuals, etc.) should not be used. Recent experience has shown that use of these figures has caused some major, expense errors by either a dealer service department, a customer, or an independent machine shop. Please inform all customers upon purchase of a shop manual, and also those customers that you are aware of that have one in their possession." This was signed by Herb Neas, National Service Manager.
There are errors above ...if you are a strict interpreter of words (millimeter should be metric Nm for instance; and 'from now on').What all this REALLY means: When BMW has a published torque figure, it is 'usually' OK as shown in Nm, (I say 'usually' because sometimes I think BMW torque values at SOME PLACES are somewhat too high). Do NOT use BMW's foot-pounds figures. I suggest that you calculate those yourself (Nm x 0.74 is foot-pounds). Clymers, Haynes, etc., have copied BMW's figures for Nm & foot-pounds & thus MAY have continued to carry forward the errors!....so be cautious. I personally know of errors even in the Factory Workshop Manuals. See article on this website: http://bmwmotorcycletech.info/torquespecs&problems.htm Torque figures in the rest of this article are values Snowbum uses, & believes to be best, proper, ... & safe.
There have been NUMEROUS instances in which someone has questioned just what BMW
means by its torque figures. This question usually arises because using a torque wrench at the limited clearance area of the driveshaft U-Joint bolts usually requires an adaptor, and BMW AND OTHERS sell adaptors ...which 'can' add to the working-length of the torque wrench, thereby INcreasing the true bolt torque value from that set on the torque wrench; unless the adaptor is used at 90°.
I know of no instances, on any BMW Airhead motorcycle, where the factory specification for torque is anything other that the ACTUAL torque on the fastener. Exceptions for R80GS, R80R, R100GS, R100R,
for torque value followed by a certain number of additional rotational degrees of tightening.
FOR R80GS, R80R, R100GS, R100R, see the note well below, under Section 11-Engine, Rod Bolts.
SO: The torque to be applied to a bolt is the factory specified torque. You MUST calculate the adjustment factor for the torque wrench if the adaptor is not used at 90° to the torque wrench. In every instance, except at 90°, the torque wrench will need to be set to
a value LESS than the specified value for the bolt.
For the curious, it is quite common for modern vehicles to have a bolt or other item specified to be torqued to a stated value, and then the item is tightened further, by a number of rotational degrees as shown on a dial.
Cylinder heads: The 4 rocker arm stud & nut threads are to be oily. If they squeak, remove nut, oil immediately, & immediately re-tighten. Evenly cross-torque, staging at ~10, ~18, & then CAREFULLY to a final value of 25 ftlbs. I ALWAYS use a final value target of 25 foot-pounds for ALL models ...even though I know PRE-Nikasil models were specified at 29-31 foot-pounds in some old literature. I do NOT consider it safe to torque higher than a TRUE 27 foot-pounds on ANY model, & that is with a KNOWN GOOD, CALIBRATED torque wrench. After the first torqueing after the heads have been off, for each later re-torqueing, back off the 2 head nuts only a very small amount, a tiny fraction of one turn, one nut at a time, & re-torque. Do same for all 4 rocker nuts, back off about 1/4 to bit more of a turn, one at a time unless doing end play work (then do both nuts of ONE rocker at one time). The idea is that you will not have more than one or two of the nuts loose, in comparison to the others, for very long. Time is involved, as I think the metal will move, so don't leave things unbalanced and loose.
Spark plugs: This section has been completely removed, updated, and moved to:
M6 nut on the end of the automatic advance unit on models through 1978:
4 foot-pounds, which is 48 inch-pounds MAXIMUM! Be careful! It is good to use a FRESH waverly washer. It is not unusual to find that someone has over-torqued this nut; yet the camshaft threaded stub end is not yet broken (& maybe not yet visibly cracked). Thus, the threads could already be weakened. Be very cautious. I always torque this nut with my experienced hand, with a very small 4 (max 6) inch wrench. If you do not have a good feel for torque, especially torque that breaks things, use a torque wrench. Use 30 INCH-pounds to start with, and preferably a fresh waverly washer. My personal limit as shown is 5 foot pounds; that means 60 INCH-pounds. I recommend 48 INCH-pounds maximum, as shown above. If you have an INCH-OUNCE wrench, guess how you calculate inch-ounces? Yes, the conversion factor is near the top of this page. Your day is ruined if you snap off the tip! So, be careful!!! The cam can be repaired in a couple of ways. See cams article: http://bmwmotorcycletech.info/cams.htm
Rocker arm adjustment lock nut: 13-16 foot-pounds (some say 12, & I am OK with that, less likely for thread problems)
Valve cover center acorn nut: 14 foot-pounds (I am cautious, & do it by feel). LOOK at the far inner end of this associated stud. It is next to the spark plug. If ALL the threads in the head are not engaged by the stud, you must decide if to remove the stud & reset it deeper (if the acorn nut with its washer will still have enough threads engaged); or, install BMW's LONGER stud, which BMW supplies just for this particular purpose. See: http://bmwmotorcycletech.info/hardware.htm.
Outer metal cover, front of engine: about 5.5 foot-pounds
Engine to frame: 55 foot-pounds is reasonable, all models, although there are differences on the books, with much lower in places, down into the thirties. I prefer 55 foot-lbs.
Crankshaft rod bolts: ALWAYS use new ones. Not rusty. Low viscosity oil, oiled threads, 36 foot-pounds. Special tri-tool needed, see tools article: http://bmwmotorcycletech.info/tools.htm. R80GS, R80R, R100GS, R100R: specifications are 15 foot-pounds, then 40 degrees more. I don't like this method, and suggest the old way, a definite torque value.
There have been a lot of different BMW specifications on flywheel bolt torque values over the years. I had previously used (clean & dry or faintest oil film from an oily cleaning solvent) torques of 42-45 foot-pounds on the 1973 & earlier engines; for the 1974 I use 52-55 ftlbs; for 1975 & later models I use about 75 to 80 ftlbs. I switched to 52-55 ftlbs for all the early bikes some time ago, and for the 11 mm bolts I still had that faint oil sheen and 75-80 ftlbs. Some aftermarket literature will show different flywheel bolt torques for different engine sizes for the same year. DISREGARD such advice. The big difference is in the size of the bolts, with the earlier 10 mm bolts using substantially less torque.
1981 & later: BMW's last specification change is in S.I. 11-049-91 (2495); this can also be seen on the 12/92 fiche on page 3, illustration G23. The SI stated that while the flywheel bolts were previously at ~75 foot-pounds (100 Nm), they were now to be at 90 foot-pounds (125 Nm), cleaned threads, & the threads were to be OILED! BMW specifically said that the bolts would NOT reach their limit of elasticity at that torque, & could be REUSED! I will NOT tighten them that tight. Makes me very nervous! However, some Pro's do oil and tighten to 90ftlbs, & I have heard of no problems reported. It is YOUR CHOICE. NOTE also that this is in regards to the 11 mm bolts, & applies to 1981+ models. For whatever reason, BMW did not mention much earlier model details.
Oil cooler hoses 17 mm banjo nuts (located at the oil filter outer cover: Absolute maximum 14.5 foot-pounds. I suggest 13 foot-pounds. Recheck after 2+ hours, or even overnight. Do not let outer hose be in contact with the fairing if you have a fairing, because fairing movement and fairing vibration might loosen the banjo. Lower hose ends fittings should not contact anything except the cover fitment area. HOLD the hose banjo bolt METAL while tightening the banjo bolt using a 17 mm socket and torque wrench, so that the banjo assembly does not rotate during tightening & touch what it shouldn't. ALWAYS 4 brand-new gasket-washers! BE SURE to check for leaks after engine startup. If you use the aluminum 'gaskets/washers'....they are to be replaced EACH TIME you unfasten the associated banjo, one on each side. If you use the copper ones, I recommend the same, although they can be re-annealed (careful heating) to be softer and mate up OK.
Following numbers have been used:
07-11-9-963-151, A12 x 17-cu These are copper, and note the 17 mm outer diameter.
07-11-9-963-132, A12 x 16-cu These are copper, and note the 16 mm outer diameter.
07-11-9-963-130, A12 x 15, 5al These are the stock aluminum washers, note the 15 mm outer diameter.
HINT! Before removing the pan, TIGHTEN all the bolts to nearly 80 INCH-POUNDS. If they tighten properly, good. If they show signs of pulling-out threads, note which ones, so you can fix the threads with a Helicoil after the pan is removed.
Oil pan mounting bolts: book values 6.5-8 ftlbs (some books show to 8.5). I suggest LESS, perhaps 5.5-6. Carefully tighten in a staggered cross-pattern, starting at the center ones and starting at a LOW TORQUE. Do tightening very evenly. NO GOO on gasket! Put the lettered side UP. There is supposedly a heat-activated glue on the gaskets. The old cork gaskets are NLA. I sometimes do these bolts BY HAND using a 4 or 6 inch wrench & not a torque wrench. MOST torque wrenches of the type that have a range of maybe 5 to 75 foot-pounds, can NOT be used for this, as their low-setting accuracy is NOT good, NOR is the FEEL OR SOUND for the click. If you use a torque wrench, use an INCH-pound or other more sensitive wrench. I recommend 66 to 72 INCH-pounds.
Cylinder head stubs: I have removed the specification because I do not believe in it. Use Loctite high temperature high strength RED. I never do this installation by torque wrench. I install the stub by feel. The torque I use is VERY TIGHT, using a strap wrench or homemade tool. To prepare: FREEZE the stub. Heat the head quite hot, at least to water sizzle. At assembly time: add Loctite RED. Use a strap wrench or other tool, and QUITE TIGHT!
Exhaust system 'clips'....pre-silencer (1985+): 15 foot-pounds
Exhaust pipe finned nuts, a YEARLY maintenance item! ::
If, in loosening a finned nut, it suddenly binds-up, then DO NOTtry to loosen with more force. By using heat, & then a penetrating oil (acetone & ATF automatic transmission fluid 50-50, shake before using), several times, maybe over a week's time, you may be able to remove the nuts withOUT cutting them! I use a mixture of acetone and Kerosene, and then ~~50% ATF oil.....as this mixture is slower to evaporate and thus does a better job, over-all, and you do not have to apply it but once or twice a day. Try SLIGHT tightening & loosening, as appropriate, flooding the threads as best possible. Heating the nut/port area before applying the mixture, will help, as the threads may draw-in a small amount of the fluid as the area cools.
If the finned nut will not come off, after all the above is tried, DO NOT FORCE IT. CUT the nut off! The nut is MUCH CHEAPER than replacing the port threads! Having to cut off the finned nut, or forcibly loosening & thereby ruining the port threads, will NOT happen if you REGULARLY maintain them, and do not over-tighten them! There is an article on this website: http://bmwmotorcycletech.info/exhaustnuts.htm LOTS more information in that article.
Use of a considerable amount of an anti-seize compound is MANDATORY!!! Failure to loosen these nuts & to clean the threads & to use fresh anti-seize compound on the threads yearly may eventually cause you a lot of anguish. Clean and coat the rings too. When cleaning the rings, clean the gap in the split ring, if you can. I use an old very thin feeler gauge for that. Rings should have their splits towards the head, that is, the tapers should face each other. I use a brass brush to clean the threads, rather than a steel brush.
Prior to 1981 the specification was 101-130 foot-pounds, later went to 145-159 foot-pounds. I have seen even higher published figures for 1981+. Problems include INcorrect conversion of Nm to Ftlbs in the literature. The proper figure is 160 Nm, which is 118 ftlbs. I NEVER MEASURE. There are steel split rings (do clean the gap) that clamp nicely inside the finned nut onto the pipe, so there is NO GOOD REASON for such tightness. I don't know how tight I usually put them, but I suspect it is not over 90 ftlbs. I also clean the pipe if crusty/rough with deposits. I never use a torque wrench, I always do it by feel, a decent grunt, using a proper finned wrench. NOT too tight, & I ALWAYS use a LOT of anti-seize compound.
Section 21-23 Clutch & transmission:
Driveshaft coupling nut (bell gear): 180 foot-pounds is the maximum and probably 150 is OK.
Swing arm allen-recess adjusters (pins): These large threaded pins with the Allen center hole are to be preloaded to 15 foot-pounds, then backed off slightly, then finished in only the tightening direction, leaving them at 7.5 (9 max) foot-pounds. At the same time you must end up such that spacing from swing arm to frame point on both sides is equal within ~.02".
Swing arm adjuster 27 mm (use MODIFIED 27 mm or MODIFIED 1-1/16" socket) thin steel lock nuts: 72-77 foot-pounds. Use a properly squared off & proper outside diameter socket. See http://bmwmotorcycletech.info/tools.htm
Preloading the pivot pins: 15 foot-pounds, then, back off, then retighten to 7.5 foot-pounds; locknuts to 75-80 foot-pounds.
Left-hand bearing pivot stub: 80 foot-pounds
Right-hand bearing pivot shaft: 3.5 foot-pounds
Right-hand bearing pivot shaft lock nut: 77 foot-pounds
BMW specifies using exceptionally strong Loctite locking compounds on the stubs and nuts. See my other articles for what I think about that, and which to use. I personally use a less strong Loctite, so they remove easier, but I add witness paint markings.
Section 31/32-Steering, forks, bars, controls on bars:
Fork drain nut: 16.6-18.6 foot pounds. Probably one should just use 17 foot pounds for all to 1980.
Fork drain BOLT (SIDE BOLT style as on later models): 6 to 7 foot-pounds (8 to 10 Nm).
Top cap nut, center tube, also called Crown Nut and Centering Nut: 80-95 foot-pounds; some books say 88-96 foot-pounds.
Top of fork tubes 'nuts' and top spring retainer: ~80 foot-pounds.
R80R, R100R, GS, top sleeve/locknut: 48 foot-pounds
M8 x 1 nut at the bottom of some forks, that holds the damper: ~15-17 foot-pounds.
Lower fork yoke stanchion clamp (lower triple clamp): 25 foot-pounds. Some variances, see your book.
Bottom caps on the lowers: specifications have varied, some say 59-73 foot-pounds; others say 87-93 foot-pounds, I do it by feel.
Damper (rod retainer nut): early bikes 17 foot-pounds; 1981 and later 25 foot-pounds (Careful!....)
Piston plugs: 18 foot-pounds
Damper slider tube, and force brace, 1985+: 11 foot-pounds
Axle clamp bolts (pinch bolts): about 10-12 foot-pounds
Axle nut: 25 (35 maximum) foot-pounds
Axle, late models, that use an allen bolt and not a nut: 25 foot-pounds
Clamp ring bolt: 8 foot-pounds
Fender brace upper: 16 foot-pounds. Be sure you know what this is.
Fender brace, lower: 1.5-1.8 foot-pounds
Fork brace, GS: 13 foot-pounds
Fork filler plugs: Varies with models: 6.5-10 foot-pounds
Handlebar nuts: 15 foot-pounds
Steering bearing preload adjustment: This should be done by road test, per my instructions elsewhere's on this site. But, there IS a specification, and it is 30 (+-2) INCH-pounds. This is the force to continue moving the entire fork, after once started moving. If you INSIST on using a torque wrench for this, ask me how to modify your existing tool tray dogbone tool.
Section 33-Rear Drive and rear shock absorbers:
Rear drive drain: 23 Nm max. I use a somewhat lower value.
Rear drive fill: 20 Nm max. I use a somewhat lower value.
Later models rear drive oil level inspection plug: This is only found on later models, & is a small 10 mm hex bolt plug, located half-way up/down the REAR arc of the rear drive. BE CAREFUL!... spec: 7-1/2 Nm, or 5.5 ftlbs, MAXIMUM. Fresh washer! I do it by feel, being careful. If using a torque wrench, use an accurate sensitive wrench, such as an inch-pound wrench. Some never remove this plug, fearing they will strip the threads. I almost never actually use a torque wrench on this inspection hole bolt/plug; doing it by educated feel. I have NEVER stripped one. I use LESS than spec on torque.
Rear drive to driveshaft housing:
Section 36-Wheels and axles (& see section 31/32, above): Axle nut: 25 (35 maximum) foot-pounds. For the /5 and /6, I suggest using exactly 30 ftlbs.
Section 46-to ? Frame, fenders, braces, saddlebag bracketry, fairings, special lighting equipment, battery bracketry, instruments pods, centerstands, etc.:
Brake caliper plugs (plugs on the bottom of the swinging ATE calipers 1974-1980): 43.3-46.6 foot-pounds. The 'book' says that the ATE swinging caliper caps are to be 45 foot-pounds for the /6 and only 30 for the /7. Why?
Brembo calipers (& ATE that are NON-swinging): Book says 22-23 foot-pounds except that the ST & G/S should be 26 ftlbs. These values are for the bolts that mount the caliper to the fork legs.
Brake caliper joining bolts, R80R, R100R: inner 22 foot-pounds, outer 7 foot-pounds.
Brake lines (pipes): 6 to 7 foot-pounds (11 maximum from 1981, but I think that too high). I suggest you be careful and not over-torque these.
Disc brake mounting nuts/bolts: 17 foot-pounds. For R80GS, R80R, R100GS, R100R, 24 ftlbs.
Axle, late models, that use an allen bolt and not a nut: 25 foot-pounds
Axle pinch bolts: front 11-12 foot pounds, rear 11-13 foot pounds; late 1984+ use 17 foot pounds on both pinch bolts; but I do not use quite that much.
REAR WHEEL BOLTS: Mono-lever models & Paralever, including R80ST, R80 G/S, R100GS, late R100RT, etc): Both three & four bolts/nuts are used on these various motorcycles. NEVER EVER oil NOR antiseize these threads; NEVER! ONLY clean & dry threads. Use 63 foot-pounds for the R80ST, & a bit more, 77 ftlbs for the G/S & 1985+ models. Values for YOUR bike are in YOUR Rider's Handbook.
Center-stand: 25-26 foot pounds (I suggest closer to 31 on 1985+ models). There are variances, as the type of bolt/nut, etc., has varied. Check your owners booklet. Many late models used 17 mm bolt/nuts & 29 Nm torque.
Side-stand center pin, from 1981: 13 foot-pounds
Rear subframe: 11-18 foot-pounds was the early original value range. I suggest you use 18 ftlbs. This applies to both the early hex head bolt and the later tapered allen head bolt.
For the carburetor band clamps, BMW DOES use a NARROW German style of screw type clamps, using bent-up ends, one fine threaded screw (usually single slot!)....and moderately tight is correct. These are NOT the same type of clamps that are available from hardware stores and other aftermarket places. These are USUALLY WIDER, and quite commonly used, but should NOT be, at certain places, such as the driveshaft rubber bellows.
Section 36-Wheels and axles (& see section 31/32, above):
Axle nut: 25 (35 maximum) foot-pounds. For the /5 and /6, I suggest using exactly 30 ftlbs.
Section 46-to ? Frame, fenders, braces, saddlebag bracketry, fairings, special lighting equipment, battery bracketry, instruments pods, centerstands, etc.:
It is NOT commonly known that American Style coarse screw-type slotted band-clamps have torque values. The type of band-clamps I am referring to are NOT the type that BMW used at the U-joint rubber bellows, which are single small screw used with a nut and the threads are very fine pitch. The ends of those BMW-used band clamps are at ~90° for the screw and nut (the nut may be bonded or otherwise secured to the band end). These band clamps are narrower than most "American" types with their large screw and slotted bands. What I am referring to here for torque values are the AFTERMARKET band clamps that have multiple cross-wise small slots almost all the way around, that you may be tempted to purchase for various things, & substitute for the original types.
A slotted band clamp:
I have never bothered to install any with a torque wrench, but, for the curious:
The standard torque setting for these aftermarket slotted band-clamps depends on the width of the band. Frankly, there are no places on BMW motorcycles for these types of clamps, but I know some of you will use them anyway at the carburetors, and maybe some places in the fuel solenoids area of later bikes, etc.
5/16" width band: 14 to 16 INCHpounds
1/2" width band: 25 to 35 INCHpounds
9/16" width band: 30 to 40 INCHpounds
There are special clamps that BMW used for high pressure fuel injection hose connections, such as for K bikes. You really should use those Oetiker types. These Oetiker clamps have also been used on
Oetiker clamp: Oetiker pliers:
What is posted in this article above IS believed correct, but no guarantees!
Initial edit & release: 07/05/2004
12/16/2004: Clarify torqueing cylinder head nuts in section 11.
02/26/2005: Layout, URL, copyright, hyperlink.
07/16/2006: Add note on calibrating the wrench.
08/20/2006: Editing for clarity.
04/25/2009: Clarify crankshaft bolt torques, to eliminate any chance of misunderstandings.
07/15/2009: Clarify rear drive to driveshaft nut tightness; minor other typos or unimportant clarifications.
10/24/2009: Clean up the article.
10/15/2012: Add QR code, add language button, update Google Ad-Sense code.
04/23/2013: Change cover from 5.0 foot-pounds.
09/25/2013: Clean up cam tip nut torque wording.
03/10/2014: Clarify, condense.
10/02/2014: Prep. for smaller devices. Clean up some.
10/25/2014: Add note #1 near top of page, and later in section 26.
08/15/2015: Clarify & expand small amounts ....and more on 08/16/2015, with some corrections.
10/11/2015: Add additional comment & cautions to oil cooler hose banjo bolts. Font size increased. Narrow & clean up article. Update Meta-codes. Clarify a few things.
02/29/2016: Add line to section 31/32...adding information on the side-bolt oil drain.
04/14/2016 : Begin to update article. Metacodes; format; horizontal lines; fonts & colors; layout.
08/21/2016: Minor correction to subframe mounting bolts in section 46.
11/21/2016: Remove Spark Plugs section and move & update ....to sparkplugs.htm article.
12/23/2016: Check metas & scripts. Revise to clean up presentation & expand some areas. Simplify HTML coding. Add band clamps photos.
02/10/2017: Improve clarity in the red box descriptions, and in a couple places in the text, particularly about rod bolts....and degree tightening.
© Copyright, 2016, R. FleischerReturn to Technical Articles LIST Page
Last check/edit: Friday, February 10, 2017