Servicing
Transmission input (clutch) splines and throwout bearing and clutch arm
cleaning, lubrication and inspection
Includes
information on swing arm locknuts, adjusters, and how to adjust those items
article #43
inputsplinesthrowout.htm
©
Applicability: All BMW Airheads, /5 and later
Skill level: lower intermediate or better
NOTE: The swing arm bearings are the common number 30203A,
although 30203 can be used. One is sealed, one not, I prefer the UNsealed
ones,
The pre-1985 wheel bearing number (all but
certain R65 models) is also the 30202 series.
Background information:
Besides avoiding SPLINE WEAR from rusting; cleaning and re-lubrication
will make operation of the clutch smoother,
and shifting easier. If kept
properly lubricated, the splines may last
almost forever; because replacing an input shaft is expensive. The clutch splines (really the transmission input shaft splines...you
NEVER
grease the clutch disc splines,
although they work with each other)... are fine toothed, and the teeth not deep, and
dryness and rusting causes problems. The normal use
of the clutch causes the clutch disc splines to slide backing and
forth along the input shaft splines, wiping away the grease. The grease
will go away after some mileage; and rusting and serious wear
begins. MANY different greases have been tried,
including some with very sticky, gummy or even taffy-like qualities;
with and without molybdenum disulfide, usually just called MOLY. If the clutch splines wear enough,
you will hear a very uncomfortable noise, and
then you are not going anyplace, as you just ripped off all the splines.
Long before this,
with dry splines, it is likely that
your downshifting will be poor.
Whenever you clean and grease those input splines,
ALSO do the throwout bearing service.
After the mid-1980's BMW supposedly nickel plated the transmission input shaft
splines and re-greasing can supposedly go to 30K miles. Sometimes,
yes, sometimes
NO. If you live/ride in wet or humid areas, check the splines at 12,000 miles, and if OK, go to 18,000. I have almost
never seen any UNplated ones go much over 20K. FEW of the plated ones go
over 30,000 miles. Those that do shorter rides, shifting a lot, in wet climates,
ESPECIALLY if engine cool-down is in a high humidity area, will need re-greasing more often than those in
dry desert climates, or those who do
mostly long rides. Every time you shut the engine
off after a
ride, the engine cools, the internal parts, including the clutch parts, condense some moisture
on them, particularly in high humidity areas. That can promote rusting
at the shaft, unless the grease is still intact. In fact, this
condensed moisture can actually promote washing-out of the
grease. For smooth operation I prefer
some
moly in that
grease, as moly tends to protect the metal from some forms of wear, and tends to
remain slippery, and even works itself into the metal somewhat.
NOTE that the Würth SIG-3000 does not LOOK like it contains regular common moly (which turns any grease rather blackish). It may be that the Würth is quite good, long term testing has begun by me. My guess is that the Würth SIG-3000 with some Honda Moly 60 added, will turn out to be as good a grease mixture as is likely to be found or made-up. I have long-term-tested many greases. The NAPA 18-9200 marine grease, the Chevron EP Ultra duty NLG1 or NLG2, Texaco Starplex with Moly, and BMW's own grease, are adequate. I do NOT recommend use of 100% Staburags, an old recommendation by BMW. Another recommended grease by BMW was Optimoly, also not so great.
What you CAN do with those above Staburags and Optimoly (or other),
if you have some of these moly greases is to ADD some, perhaps 1/3, to
the
non-moly greases like the Chevron. There is NO
perfect grease, that I know of, for this application!!!
What I like about the SIG-3000, so far, is that it is very tacky.
I do NOT think it, alone, is near optimum...but with moly,
perhaps quite good.
Honda Moly 60 grease is available at their motorcycle dealerships, and in larger tubes,
at the Honda car dealerships. These have a
but rather thick but high moly content. Folks
have used this by itself, with decently good results.
My chemicals, etc., article has
more info.
The throwout bearing (this is the
bearing INSIDE the rear hole at the rear of the transmission...I do not mean
the clutch arm lever bearing) is easy to get to
after the lever is removed:
***NOTE! DO see the Clutch article which goes into this area in more depth:
CLICK!
There have been three general types of throwout bearings
used INSIDE the transmission rear housing. In the /5, there was a ball
bearing. It gives little
trouble. From the /6 into 1984, BMW used a flat radial needle bearing. It is troublesome if not kept lubricated
and in good
condition. NOTE that all these throwout bearings are supposedly
lubricated by the transmission oil. That is true, but when
cleaning one of
these throwout bearings, I strongly suggest you use a plain soft non-moly grease
on them, and the piston, etc. That is because it can
take quite awhile for the transmission oil to get to and
lubricate the bearing. The radial bearing is a POOR design. When RADIAL needle bearings
are rotated circularly, the needles try to rotate at the same speed at BOTH
ENDS of each needle....that is, from end to end of an individual
needle. This is NOT POSSIBLE, if you think about it, so
they scrape around....moving the grease out of themselves.
If the grease (or transmission oil) is not there, and a little
moisture condenses there, or excessive clutch hold-in times are
often used ....and/or combinations of these things.....the
bearing can start to deplete its lubrication, and actually freeze up.
****There is also a problem in the many models that have
the throwout piston separate from the bearing....in
that the PISTON that drives the bearing
has a plastic outer body (doesn't look
like plastic though, looks like some sort of metal). Plastic expands vastly faster than the aluminum
transmission bore....and some pistons were made slightly too large in diameter, and could
freeze up somewhat, when the transmission
got hot. Makes for lousy
shifting. After 1984, BMW went back to a type of
ball-bearing design. BMW makes a pricey replacement
for the
earlier piston that was too large in diameter, and that new part also now
contains the bearing as
part of the assembly. You can easily fix
a sticky plastic piston however; and save lots of money.
This fix is done by cleaning it, and then chucking the small steel nub into a drill
press, and then using sandpaper squarely and evenly against the outside plastic
diameter. Information LATER in this article gives more details.
NOTE!....it
has been reported to me that BMW is now shipping an all-plastic part that has
the same old problems!....so, be sure that no matter what part you have in YOUR
bike, that it is not expanding and seizing up!
Again, be sure to see the CLUTCH.htm article on this website, it has a lot of information, photos of the throwout parts, etc.
The FIRST sign of impending bearing problems is USUALLY, but not always, a
stiffening of clutch action, and/or some strange noises.
If you keep
your bearing clean and greased....say at every spline lube job (15,000 to 20,000
miles usually), then you are far less likely
to have a problem that will strand
you during a ride.
What follows is a step by step HOW-TO article, on
cleaning and lubricating the throwout bearing, inspecting for any damage, and a
modification if needed; and, inspection, cleaning and lubricating the input
splines. While the procedure was developed from both a
1983 and 1984
R100RT, some generic information is included, and this procedure should be
easily adaptable for YOUR bike. There
are specific reasons the
author did certain of the steps in the order shown.
Note: This procedure does not require
many special tools. Tools from your on-bike BMW tool kit are needed. Also needed
are the proper grease
for the splines; a grease gun with a rubber tip that can
contain almost any chassis grease (for the swing arm greasing); a modified 27 mm
or modified
1-1/16th inch
socket; a torque wrench; 13 mm socket; 3/8 or 1/2 inch drive as appropriate with
a standard extension; 6 mm allen wrench in square
drive; 6 mm standard BMW tool
kit Allen wrench, with the short side shortened...this is for the lower left
transmission bolt; anti-seize compound, rags, cleaners; two acid brushes
(modified); and two pieces of almost any small rod or
yardstick, etc., and a few minor items you are very likely to have.
It is
handy to have a modified Chinese bottle jack,
an article on that modification is on this website...and that WAS a hyperlink,
although it is listed
on the Tech Index page as item #20. The tools
above are not to be
construed as an exact list of items you will need. You may improvise
for YOUR
bike as needed. Some folks with
smog parts may need a 15/16" flare nut wrench or substitute.
NOTE: You can elect to totally remove the
transmission,
which is a more work, you may have to remove the
driveshaft, shock absorbers, battery tray, etc...or do it how I
show it below. Do
NOT overly grease the
input shaft. Follow directions!
REFERENCE: 07-11-9-918-655 50 mm Allen head bolt with captive washer; 07-11-9-901-033 45 mm bolt or
07-11-9-901-161 40 mm bolt.
In case you decide to replace the upper
right stud. See text.
Regarding the modified 27 mm or 1-1/16" socket:
Obtain
a standard 12 point socket, NOT a 6 point.
Square off
the large working END of the
socket until
all of
the
small
amount of INside taper is gone. You can do
this BEST by chucking the socket in a lathe; but can be done if
VERY
careful about flatness AND squareness, using a grinding wheel or
flat sander. The
lathe does the best job, and it is worth having this done
properly
if you do not have a lathe. This covers the
working INSIDE END of the socket...but the socket needs one more fix:
Remove one of the plastic
caps over one swing arm adjustment area. Take a
careful look at the inside diameter(s) of the swing arm nut/adjuster
cavity. You will probably see
TWO diameters. Turn the outside of
this socket on a lathe, or by hand on a grinder (crudeness is OK), so that the socket will fit very
easily through
both diameters in the swing arm cavity and the newly
'made square' end of the socket fits
FULLY over the 27 mm nut. Do not turn/grind the socket
too much, nor
too little. Too much and the socket is weakened (another reason for a 12
point, not 6 point), too little and the socket will not pass
easily by BOTH of the
internal swing arm cavity diameters. SOMEtimes BMW did machine those two diameters concentric
and very nearly the same
size.
See near end of this article on just how the swing arm is adjusted.
1. There are two articles, besides my clutch
article on this website, that you might want to read, and use the information in those articles as an adjunct to THIS
article. Those articles are at:
http://www.airheads.org
Click your mouse on the left side at Technical Tips.
Read the articles on the throwout bearing by Matt Parkhouse,
dated 12/99; and mine, on Lubing the Transmission/Clutch Splines,
dated 12/04. Those articles are slightly out of date, but
may prove useful to you. Reading those two articles MAY
give you somewhat different perspective on the article you are
presently reading.
2. Remove the gas tank. Engage 5th gear on the transmission (4th
on /5) and leave it engaged.
3. Remove the clutch actuating arm at
the rear of the transmission. There were TWO basic styles
of these arms. One earlier style is held in place by
a steel pin that has
a groove, said groove has a C-clip, and the clip is located at the lower area of
the INSIDE between the transmission ears. If you
have a /5, you have a cotter pin to the boss. Be SURE that when you reinstall
the clutch lever arm that the C clip fits TIGHTLY, and is for
sure fully in its
groove. Be SURE! If the clip falls out, and the pin comes
partially out, actuating of the bars lever will BREAK OFF a transmission
ear,
stranding you. The early style arm also has a grease
fitting, and the throwout parts are different. The later style arm
uses a 10 mm bolt with waverly locking washers, and NO C-clip. Insert the
bolt so the nut is at the LOWER area. I prefer a Nyloc type of nut. The later arm has no
grease fitting.
...read all of #13 below.
You can now remove the clamp, and boot, if you have those. You will find a
coil spring inside the boot if you have a boot.
4. If the arm is the late style, push through
the steel sleeve (if you can easily) and in any event do clean
the arm bearing and lubricate it with OIL. I coat
the outer faces (where the arm rubs the transmission ears) lightly with
moly grease. It is QUITE common to see arm needle bearings as having
NEVER been cleaned and oiled since new...and you can try a bit of heat and
cooling to suck in some oil...sometimes that works on really frozen up
ones.
For the /5, grease the fitting, cleaning innards first.
Clean the bolt or pin and very lightly oil its surface. Remove
the throwout bearing, do not try to
remove the inner central rod that is forward
of the throwout bearing. The earliest style bearing had BALL bearings, the
later not as good style (/6 to
about 1984) had a flat radial needle/roller
bearing, and after 1984 it supposedly is a ball bearing again. There is some variance
in the outer spring and
black rubber cup, and the single or two part piston,
ETC. Ball bearing types have been
seen on years they were not supposedly on, some 1984 for instance.
NOTE: Tolerances have varied on the diameter on some transmission throwout
bores, and throwout piston tolerances were not
held tight enough.
Generally this is thought of as from 1981, when BMW
changed the clutch design radically. If the
piston fits into the bore a bit too tightly...it may still
operate smooth enough
when cool, but under some circumstances, as the transmission fully
heats up, may stick. Measure the piston,
and if it is over
about 1.13" (28.7 mm), you MAY want to reduce the outside
diameter a bit. I have seen these as large as about 1.142" that still
worked OK. I can't
give a hard and fast rule here, but if yours is up to
1.141 or so, I would certainly see how it fits, and if a bit too much friction,
I would recommend
sanding the OD a bit. Remember that to REALLY test the
fit, you have to HEAT the piston fairly hot! I have done that, it
this works well to determine
if the fit is OK. You can chuck the rather
short shaft tip end in a drill press and use some rather fine sandpaper for
reducing the diameter.
Inspect the
bearing, and if it looks bad, replace it. Grease it with a
good thin grease (NO moly). Yes, I know transmission oil will eventually, one
hopes, dissolve the
grease and lubricate the bearing with oil.
Set the now cleaned and lubricated arm and throwout associated
parts aside. It is MUCH easier to move the transmission far enough to
the
rear for the input splines greasing, with the clutch lever removed. In
fact, without the lever removed, you probably can not do the
splines
properly. DO NOT injure the transmission ears in any of your work!! KEEP FILTH AWAY FROM THE PARTS YOU JUST CLEANED AND LUBRICATED.
5. Remove the airbox and airfilter. If you have the older
clamshell type housing you will have to push the breather hose out of the
half. If you have the
later square housing, and depending on what is in
the area (pulse air parts, breather hose setup, vacuum line setup, etc.), you may
have to move the
breather hose forward. Replacing it can be a bit of fun,
and it is easier at that time, to simply remove the starter motor cover...and you
CAN do that now. With the starter cover off, it is a great
time to check the nuts on the electrical post of the starter. If
you've have had breather problems, now is a great
time to fix whatever is wrong.
On late model airheads, you can inspect the solenoids and vent into the
crankcase, and decide whether or not to modify
them. You may even want to
change an early model disc breather to a later reed type, and clear the bottom
of the cavity small drain hole in the breather
area (not early models prior to later seventies)....see information
elsewhere's on this site. There is nothing wrong with
using the original early disc-type
breather, if in good condition; you could even make a
replacement; or, install the later reed type.
6. Remove what vacuum and smog parts, if any, that you need to on your particular
bike (you may want to modify at this time or before re-assembly). Remove the left lower bolt on the transmission, and the
right lower bolt. NOTE the brown grounding wire at the left lower bolt if
you have that. Pay
attention to washers. Remove the left upper
bolt. Remove the nut on the right upper STUD. SOME folks may want to
fully remove the transmission:
add a nut, lock the nuts together, and thus remove that stud. THAT
IS...you may want to consider changing that stud to a bolt. The twin nut is
fine,
can be left in place that way, and you don't REALLY have to remove the
stud...for the SPLINE service. Removing the stud on some models makes
removing the transmission and other servicing a bit easier, and USUALLY the
battery and battery box need NOT be removed. Your choice here.
If you decide to remove the transmission, unfasten the driveshaft
U-joint from the transmission, remove the swing arm
adjusters.....this is a good time
to inspect the 4 special bolts that hold the U-joint...they must
be the correct later shorter length and NO!!! lockwashers!!!
(Loctite blue is used on the
threads).
If you have the rectangular airbox, remove the 13 mm hex
headed bolt that goes straight down through the top, middle, of the
transmission. Removing
that 13 mm headed bolt is NOT needed on the clamshell airboxes.
IF you removed that bolt, then when you REinstall that bolt later, coat the first few
threads AND
THE WASHER with a non-hardening thread sealant, such as
Permatex Form-A-Gasket #2. If that bolt is loose, or leaks,
oil will be
sucked out of the transmission. If you have the rectangular airbox, you should now be able to remove the base
box.
NOTE: BMW uses a metric size for vacuum line crossover hose and for the
gas line crossover hose that pass through the area. Use of SAE
(American, inch size) hose will make for more difficult fitment. I
recommend the stock BMW black hose. If you have a classic /5, and want to
keep
it original, you can get the original silver braded fuel hose from Bing Agency.
I don't think it is as good as the later black BMW metric fuel
hose.
7. HINT! Some folks have a hard time
removing and replacing the plastic input tubes to the carburetors.
On some models, these
tubes are not the same, left to right, and also ARE NOT the same end for end, and only one fits the proper left or right side, and only
one end of THAT fits the airbox and carburetor. MARK
yours before removing! (such as: left, to carb; or, right,
to carb). For the
rectangular airboxes, and to some minor extent the clamshell type, it is FAR easier to leave
these plastic tubes attached to the airbox
half or base, and to loosen the
clamp(s) at the carburetor end of them and when the the airbox is
removed (especially, that rectangular
box), the whole assembly lifts off easily, and replaces
more easily. If those plastic tubes are off
and the rectangular box is already
installed...,try fitting the carbs and intake hoses and plastic
tubes all as one assembly at one time.
8. Using the Chinese jack as modified, or some other means, typically
at the rear lower frame crossover tube (not as easy for a model with the
pre-muffler under the transmission area); jack the rear tire barely off the
ground. If you have a ride-off stand you may want to find a way to put a
3/4 inch or so piece of plywood under the ride-off stand by
rocking the stand left/right, as you install a board. Bikes vary, play
with yours until you
find out what is needed. Remove the plastic covers
over the swing arm adjusters, and loosen the two 27 mm nuts, maybe only 1/4-1/2
turn loosening
is needed, and then UNscrew the allen-center adjuster on each side, and REMOVE the adjuster with the nut still
attached. You may have to
wiggle the tire/swing arm a bit to allow the
adjusters to be removed, and that helps avoid damaging the threads. I have seen these not lubricated
properly and rusted badly. I have seen the bearings rusted
bad enough to crack! If yours are at all bad, I recommend you
remove the entire rear
end of the bike and service the swing arm bearing
area. Various puller
styles will work to remove the outer bearing race, Ed Korn (see
tools.htm
article) made a cute one, and
in a kit to install the new one. It is a simple job. The swing
arm bearing is basically the same as the wheel bearing, a
common type from any
bearing supply company. I prefer not to use sealed versions of those
bearings (or, I remove the seal), allowing ME to grease
from the outside, after
the bike is reassembled, via the center Allen wrench hole in the
threaded pin adjustor.
9. There is typically no need to undo any shift linkage for just a
spline re-lubrication. You DO have to undo the
wing-nut on the rear brake rod,
if you have a drear drum brake.
10. Pull rearward on the transmission. It will likely come
backwards a wee bit. The limit for the rear movement is typically not the
clutch ears but the driveshaft housing interfering with the frame cross
tube. You will probably find you need to HOLD the transmission
backwards. While you can use
some pieces of WOOD (NOT
METAL!!) to wedge into
the transmission-engine opening (and may end up doing that anyway), you MAY want
to
fashion some means to KEEP the suspension moved to the rear. I do this
by hooking a STRONG bungee from a lower spring/shock unit, back to the
turn signal tube,
VERY tightly (on both sides if a twin shock model). If you play with the transmission
and rear end movement a bit, you will find that
you can separate the
transmission from the engine JUST enough so that the input shaft forward end is
visible.
****NOTE! It is not uncommon for someone to complain that
the transmission will not move backwards much. See #9, just
above!!
****NOTE! If you see an OILY spline at
the transmission and see oil coming from the
input end of the transmission, you MUST undo the universal
joint, remove the
transmission entirely, and replace the transmission input seal. Failure to do that will
result in eventually oiling the clutch. This is an
easy job if the
transmission is out, you do NOT have to take the transmission
apart. Some may prefer to totally remove the
transmission, and clean
the area at the clutch and transmission, check for leaking oil
pump seal, leaking main seal, etc. NOT mandatory unless you
see leaks.
Ideally, the transmission, when in the bike, is back far
enough to see the clutch end (that input shaft end I mentioned
just above) of the transmission
input spline. It is nice to be able to get
the center rod to the rear enough to get to that tip with one
droplet of lube, later.
11. Blow out any dust and dirt from the area. Do that now, rather
than later. DO NOT breath that
dust. Under NO
circumstances allow
any prying with metal tools that will nick the
transmission-engine mating surfaces,
thereby causing the transmission not to re-assemble dead squarely
to the
engine. CLEAN the splines of the INPUT shaft
(NOT clutch disc!). If the rear center of the clutch disc
(spline area outsides) is very greasy,
clean with a rag.
To both clean and grease the transmission shaft input splines, I make up TWO simple tools:
Take two common acid brushes. Cut the bristles down in length,
by maybe nearly 1/2, so they
are a stiffer. Tape or otherwise tie securely those
brushes to some
sort of thin rods or any similar items, such that the brush handle length
is extended. ONE brush tool is your permanent tool for
cleaning, the other is
for your permanent tool for greasing. You only need make these two once,
so after you are done with them, put them on your
shelf of BMW tools. I
use wood dowels from the hardware store. I am guessing mine are maybe 3/8"
in diameter.
To clean the splines, use some sort of strong petroleum-based solvent on one of the
brushes, and move the brush back and forth along the INPUT
spline; that is, the
TRANSMISSION spline. Rotate the
spline as need be, by rotating the rear wheel (which is off the ground and the
transmission is
still in top gear). I like to finish the INPUT spline by spraying a
good cleaner on it, but remember, do NOT clean the spline of the disc!...except
to wipe
with a rag if need be. If you spray solvent into the
clutch disc splines, that can easily put grease/oil/grunge, into the friction
disc....so do NOT do that. Common BRAKE CLEANER does NOT do a good
job for cleaning. I use acetone, MEK, or similar strong and fast
evaporating solvents.
Berryman B12 carburetor and choke cleaner in the spray can, with
a spray wand, is exceptionally good!!
IF that area shows OIL leakage from the
transmission, remove the transmission and replace that seal...and
ask the LIST how to do that! It is not
difficult and you do not need to
disassemble the transmission. Failure to replace a
leaky seal will ruin your clutch eventually. There are TWO ways
transmission oil can get into your clutch. ONE is via a bad transmission
input shaft seal. The other is a missing round tubular FELT, that can be
somewhat of a devil to install, located, hidden, around the rod that passes from the rear
throwout bearing area to the tip of the input shaft. It is
easier
to install that from the forward nose (input shaft spline end). If you have
NOT removed the transmission, you have likely not been able to remove
that rod
accidentally, so, you should have no problem with that felt at this point,
as the felts last darn near forever.
Grease the INPUT SHAFT splines once the solvent is totally evaporated. Work the
grease into the splines, bit by bit, all around, using the greasing
brush tool. It is not needed, nor
desirable for too much grease.
If the rod END that is in the center of the input shaft is not visible, make it
visible. This is usually easy with the clutch lever having been removed at
the
rear. You can either grip the rod at the rear, or use the end of a
screwdriver against the forward end of that metal rod, to move it rearward to see the tip. Put
ONE SMALL drop of moly grease on the tip, and putting one at the rear is a good
idea too.
Clean the surfaces of the transmission shell that will contact the engine surfaces. Take your time to do this properly. Under NO circumstances are any nicks, nor filth, allowable that would keep the transmission from SQUARELY and FULLY mating to the engine surface. Clean the engine mounting surface too.
12. Reassemble everything, bit by bit, slowly, and carefully.
Do
NOT allow foreign matter to interfere with the transmission coming up to the
engine
cleanly, and squarely, and fully. Be sure the transmission is fitting squarely,
and
then cinch up the bolts, evenly, in a cross pattern. Do not forget the
vertical 13 mm bolt (you HAVE used a sealant on that
bolt and washer??). The clam shell
model requires the right clam shell to be in place for this.
Do NOT forget
the grounding wire. You can now reinstall the clutch lever at the
rear....and do any cleaning and lubrication there that you did not do
previously.
***After
the adjusters and locknuts are replaced into the frame cavities and engaging the
swing arm, these adjusters (pivot bolts) need to be adjusted.
If you did not move the locknuts originally except perhaps 1/2 turn, or 1 turn,
as
needed to just loosen them, it will be a bit quicker. In any case, what
you
must do is screw both
adjusters inward with an Allen wrench, a bit and as evenly as you
can on each side. DO NOT try to
really tighten them much.
Try to keep the swing arm roughly
centered in the frame. You
can use a small allen wrench from the BMW on-bike tool kit, or a selected
diameter of
drill shank, using them as a thickness gauge, placed between the FRAME and the SWING ARM, to get the
swing arm centered in the frame. This may
take a few attempts until the
swing arm is centered; that is, the selected size of drill shank or allen wrench inserted between
frame and swing arm shows
the same spacing, side to side.
What you will then do is torque one of the adjusters to 15 ftlbs, back off a bit, re-torque to 7-1/2
foot pounds,
stopping at 7-1/2 whilst going in the clockwise tightening direction.
If the
spacing is now fairly equal, fine, if not, back off one adjuster, tighten the other,
in the
same manner, and repeat until near perfect, then tighten the 27 mm thin
STEEL nuts to 70 to 75
foot pounds. Some folks paint mark the
adjusters to be sure that
they do not move whilst the 27 mm nut is being tightened, usually they do not
move.
There is nothing super-critical about the equality of the spacing. If you are within 0.15" or .020", that is good enough.
NOTE!!....just to be sure there is NO confusion here.....there will be NO
feelable side to side freeplay in the swing arm to frame mounting, when you
have
adjusted the pivot adjusters properly. You are taking up all free
play, equally spacing the swing arm in the frame (side to side), and then
leaving
the adjustors with some torque on them, specified at 7-1/2 footpounds,
AFTER first torquing to 15 footpounds, backing off, and resetting to 7-1/2.
Obviously, setting one side presses the swing arm against the other side, so you
can't do both at the same time together. You do the centering
adjustment,
bring the pivot adjusters close to correctness, and then adjust ONE side for
proper torque, and see if the other side and the first side match in DISTANCE.
Once you have done this once, you will find it very easy.
Use your torque wrench with the Allen of 6 mm size, the other end
the square drive
to match your torque wrench.
NOTE!! I grease my swing arm roughly twice a year, depending on my
traveling conditions. I grease both sides with my rubber pointy tipped grease
gun with the tapered rubber tip (common item, NAPA stores). Every few years I pull
the entire rear structure backwards enough to hand-clean and
eyeball inspect,
and finger-feel, the condition of the bearings. You can
also use a chain saw grease gun with pointy tip. At one
time there was a
BMW grease gun.
I use a fair amount of grease, and then I use my fingertip to wipe the excess
grease, all-around, down to smooth coverage.
That way, any water getting
in the area will see a layer of grease in that 'cavity' for which you set the
equality distance. I prefer the NON-sealed
bearings, so all this greasing works properly. If I have a
sealed bearing, I may destroy the seal first. Late models may have sealed swing arm bearings....
I have seen a
few earlier models with this type....and with an intact seal you have to go about greasing things differently....like with a sharp grease
needle from the side;....through the seal.....etc.
Every few years it is not a bad idea to remove the swing arm...or
move it backwards...enough to do a thorough bearing service.
As noted, I like to
leave
enough grease in the measured space area that rain, washing, etc. does not get
in there. As mentioned, a sealed bearing is not needed. In fact,
the
R45/R65 models came without one spacer and grease containment item. If I find the bearing sealed, I usually prick or otherwise
actually on
purpose damage
the seal, so greasing goes to the proper areas. The bearing is the
same type and size as used on the PRE-1985 wheel bearings....
type 30203, a very
common part.
13. If not already done, add a wee dab of moly grease to the working end of the clutch arm
where it fits against the rod in the transmission and
re-install the clutch arm and associated parts.
AGAIN, I caution that if you have the early style lever that uses the pin with the C-clip, it MUST be
installed properly...better yet, change it, so read onwards, and refer back to
#3:
The /5 uses a cotter pin; totally reliable. The later models
use a bolt, put the bolt in from the top. Watch how the arm is installed, even on the later
models. The arm thickness with its sleeve, whatever, is such that you
should not be able to break the ears off the transmission. IT
CAN HAPPEN>
WATCH what you
are doing! Refer back to #3. Adjust the
clutch per the book if need be. You normally will not have to if it was OK
before
you started all this. It is a darn good idea to lubricate the two
barrels of the clutch cable, one at the bars, one at the lever at the
transmission. At the
lever at the handlebars, inspect to be sure that the cable is NOT being fouled by the
lever movement,
and all strands are INTACT!
From the 1980 model, BMW changed that pin through the clutch lever at the rear
of the transmission. This is easily fitted to earlier 5 speed
transmissions.
This is a mushroom headed pin part 23-13-1-241-484 with clip 51-23-1-864-963. HINT!....Early models had the clutch actuating lever at the rear
of
the transmission held to the two bosses of the transmission cover by a PIN, that
used a single C clip. That C-clip fit on the pin at the INside of the
lower boss. If the clip came loose, or was not fitted fully, the pin could come upwards, and come
out of the lower boss, and the next clutch application
could, and often did,
break off a transmission boss ear...necessitating a transmission overhaul....or
some inert gas welding at a minimum. A cure is to
remove the old pin
and clip and install the above two parts.
14. The adjustment of the early style (up to 1980) and the 1981+
style clutch/levers is different. They end up being about the
same though. About
3/32" of free play at the inner opening point of
the bar lever is about right, and the lever at the transmission will be parallel
with the transmission rear
with the bar lever pulled half way. For the
1981+ bikes, the tip of the transmission mounted lever should be 5.0 inches from
the cable boss with the
lever NOT being actuated at the bars. Set the lever at the bars via the adjustment in the
clutch arm; and the transmission lever via the bars knurled nut;
exactly opposite of what common sense would seem to tell you. For the
1981+ bikes, the transmission mounted lever will actually face rearward about
4°.
Revisions:
01-15-2003: Clarify and add to tools list; add applicability and skill
level; add reference note on 50,45, 40 mm bolts.
01-22-2003: Add section on adjusting the swing arm, and modify here and
there to incorporate clarity for that, add hyperlink within the page for that
adjustment. Add #13.
04-16-2003: add .htm title; clarify many details.
05/06/2003: add note on ball type throwout bearing seen on 1984; note to
coat the 13 mm bolt's WASHER in top of transmission; typos; input seal note in
#10; clarifications
05/11/2003: rework #12, to eliminate one reported incident of someone
managing to jam something or other. How???
05/15/2003: correct typo, 1-1/6" should be 1-1/16".
07/26/2003: expand #13, add ref to #3, and add #14
08/28/2003: add #15.
11/21/2004: remove #15, back into #13, and references to #3 added as
necessary.
06/01/2005: bearing number added
07/10/2005: updated to eliminate some confusion in procedure
07/11/2005: additional small changes on adjusting swing arm, and about the
seals there
07/23/2007: Some editing for clarity
11/04/2008: In item 13, change part number of pin from 23-21-1-241-484 to
proper 23-13-1-241-484
12/05/2008: Update item 12 for clarity.
08/31/2009: minor clarifications
10/27/2009: Clarify a lot more details
10/28/2009: Add wing-nut information, #9, #10.
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