Torque
values for various fasteners on the various models of airheads
©
torquevalues.htm-71B
Be sure to go back and read part 71A, if you have not previously, before using this part 71B.
This article, 71B, is basically a listing of values for torque wrench settings for various places on the various models.
To convert torque wrench settings/values between
systems of measurement:
Nm x 0.7376 = foot-pounds
foot-pounds x 1.356 = Nm
Mkp x 7.23 = foot-pounds
inch-ounces = 141.6 x Nm
Mkp x 9.81 = Nm
NOTE! When threads are clean and dry, and then Loctite is used on them, as a rough guide, Loctite causes about a 15% increase in actual torque (acts as a very mild lubricant). Because of the safety factor of parts strengths and typical usages, the effect of Loctite is usually ignored, as far as torque wrench settings are concerned. This is NOT SO when using antiseize compound...you should, and in many cases (spark plug threads) MUST allow for the change (30% approximately with antiseize compound).
NOTE! Fittings from Germany are specified by a
different grading system from that used in the U.S.
Bolts are marked on the heads by a number, that corresponds to the over-all
strength rating. Tables listing certain specifications such as plating of
steel bolts and those then screwed into, say, aluminum, are not a normal
item as shown. Ratings (grades) used in this DIN
system FOR BOLTS and SCREWS are, in increasing order of strength: 5.6; 6.8; 6.9; 8.8; 10.9; and 12.9.
The 8.8 is a fairly strong metal, and is quite common on BMW's. Whilst 8.8
is commonly available in hardware stores, many such stores carry INFERIOR bolts,
often unmarked...and in SOME instances, you can NOT depend on the
markings! BMW uses some even stronger than 8.8 rated bolts in SOME SPECIAL
INSTANCES....shock absorber mounts, brakes, rods, crankshaft-to-flywheel...etc.
I suggest using BMW-supplied parts!
There are standardized tables for recommended tightening
torque for fasteners, these common tables have the size of the fastener
(M6, M8, M12, etc.) and the optimum tightening torque for the grade. In
the DIN system, bolts are assumed to be phosphate
treated, no after-treatment, not galvanized. There is, or may be, information on
oiled versus not oiled. Separate tables for cadmium plating are available
(approx. 30% less is the recommended torque for cadmium
plating). Tables are different for NUTS; and nuts are rated
as 8, 10, and 12 in strength....and the same sort of messiness occurs with
plating, lubrication, etc. It can get complicated, with a nut and bolt of
different ratings. As a general rule, there are some standards for
all the various types of headed screws, bolts, etc. All
this, and the tables, can often be pretty much ignored....unless YOU are doing
something special, or if there is no specification by BMW for your specific
fastener, and I CAN, then, supply the information, it is way too extensive to
be listed in this article. So, in tightening fasteners on
your BMW, use the information below, and if something is not listed, ask on the
Airheads LIST.
NOTE!!!!.....BMW is shipping parts that are NO LONGER cadmium plated. These parts tend to RUST! Try to obtain old original parts. I think that the lack of cadmium plating is some sort of environmental rule in Europe. Also note that in some circumstances, BMW is shipping bolts with 1 size smaller heads, under the SAME part number. Often a dealership will, thusly, have BOTH sizes of bolt heads in the same box on their shelves. I offer this caution, because, as an example, you might not have 18 and 16 mm wrenches in your tool kit!...the 18 being substituted for 19mm, the 16 for 17 mm. Note that late model BMW motorcycles are using the smaller heads, generally. You will likely see this on early K-bikes, for instance...and carried forward to present production.
NOTE: 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.
NOTE, from me, Snowbum: There are errors above
(millimeter should be metric for instance, especially torque). Let me spell this
all out
simply
for what it REALLY
means...AND, note that BMW does not directly admit that THEY made
errors...weasel wording, EH?!?
When BMW has a published torque figure, it is 'usually' OK as shown
in Nm,
but do NOT use BMW's foot-pounds figures, shown as (xxxx), calculate them
yourself (Nm x 0.74 is foot-pounds). Clymers, Haynes, etc., have used
BMW's figures for Nm and footpounds, and thus MAY have continued to carry
forward the errors....so be cautious.
I personally know of errors in even the Factory Workshop Manual.....see article
on this website: Torquespecs&problems.htm.
Section 11-Engine
Cylinder heads: Evenly cross-torqued, staging at 10 to 11, 18 to 20, then
CAREFULLY to a final value of 26 foot-pounds. I use a final value of 26 foot-pounds for ALL models...even though
I know PRE-Nikasil models are specified at 29-31 foot-pounds. I do NOT consider it safe to torque higher than 26 footpounds on ANY
model, and THAT is with a known GOOD torque wrench! The
4 rocker arm nut threads are to be oily, and if they squeak, remove nut, oil immediately,
and immediately retighten. 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, one at a time, and thenretorque. Do same for the 4 rocker nuts, but
back off about 1/4th turn, one at a time unless doing end play work (then do
both at one time). The idea is not to have just one or two of
the nuts loose, in comparison to the others, for very long.
Spark plugs: 16-18 foot-pounds for clean and dry threads for the 3/4 inch
reach stock top plugs. SOME old manuals will show values as high as 21.7...do
NOT use such high values!! For use with antiseize
compound, reduce the 16-18 ftlb figures about 30%, I use about 14 ftlbs. For the
bottom 1/2" reach 14 mm plugs, specification is about 12-14
foot-pounds on clean and dry
threads....be very cautious, use about 10-12 ftlbs if anti-seize is used. If you have
12 mm 1/2" reach bottom plugs, use a bit less with antiseize compound.
Anti-seize compound works into metal, so be cautious if you install spark plugs
without such compound if the compound was used
previously. Doing it by feel on a fresh crush washer works quite
well, provided you are not ham-fisted.
M6 nut on the end of the automatic advance unit on models up through 1978:
4 to 4.5 foot-pounds. Be careful!
Rocker arm adjustment lock nut 13-16 foot-pounds (some say 12, and I
agree)
Valve cover center acorn nut: 14 foot-pounds
Outer cover, front of engine: about 5.5 foot-pounds
Engine to frame: 55 foot-pounds is reasonable for all
models, although there are differences on the books.
Crankshaft rod bolts: except as below, ALWAYS new ones, 36 foot-pounds
R80GS, R80R, R100GS,
R100R: 15 foot-pounds, then 40 degrees more.
Flywheel bolts, ALWAYS new ones are recommended,
but NEVER reuse the early smaller /5 type bolts:
/5 (smaller diameter, 10 mm bolts): 44 foot-pounds
1974: two specifications, 45
for R60 and R75, then 53 on R90 series, but I
simply use 53+ foot-pounds
1975 and later, earlier
specifications, 11 mm bolts: 76 foot-pounds
BMW latest specification change per
S.I 11-049-91 (2495):
90 foot-pounds, and oiled threads!....(I won't do them
that tight, perhaps it is OK, I
honestly have reservations on oiled flywheel bolts at 90!).
Oil cooler hose banjo nuts: absolute maximum 14.5
foot-pounds. I suggest 13 foot-pounds, rechecked overnight.
HINT: do not let outer hose be
in contact with the fairing if you have one.
Oil pan mounting bolts: book values 6.5-8.7 foot-pounds,
I suggest less, perhaps 5.5-6, carefully tighten in a
staggered cross-pattern, evenly. NO
GOO! Put the lettered side UP. There is a heat-activated glue on
these. BTW...
the old cork
gaskets are NLA. I do these BY HAND, not torque wrench. YOU may want
a wrench!
Engine oil pan drain: 20-22 foot-pounds (book values
have been variously from 20-25).
Oil filter inner cap bolt: 15-20 foot-pounds (some books may
say 30, I feel that is too high).
Oil filter outer cover plate, no matter if thermostat or GS
or plain: not over 7.5 foot-pounds.
Oil pressure sending switch: no specification on early
models, later models from about 1985 or so specify 18 foot-pounds
Use 12 point deep socket, moderately tight by feel. Do NOT overtighten.
Oil pickup bolts: 6.5 foot-pounds, Loctite BLUE
Oil PUMP cover: 88 INCH-pounds;
probably 72 is enough though, for any oil pump cover bolt.
Camshaft flange bearing and front main bearing: 11-13 foot-pounds,
but some models from about 1985 are 18 foot-pounds.
Chain cover: 5 foot-pounds
Section 12-Engine electrics
Spark plugs: see Section 11
Centrifugal advance, old style, single M6 nut on end of
camshaft, see section 11.
Starter motor bolts: 35 foot-pounds is the published
specification, but this is probably excessive. Be very
cautious that the starter is solidly squarely in place as you tighten.
Alternator rotor allen bolt in center: book value is
17-20, I suggest perhaps 12-14 or tad more. The
rotor-to-engine-crankshaft is a taper-fit and the mating surfaces must be
absolutely clean and free from any contamination, including oil, even
fingerprints. Do NOT use gasoline in cleaning.
Section 13/16-Carburettors and associated air and fuel inlet parts
Cylinder head stubs: 10 foot-pounds,
Loctite RED.
NOTE: I do this by
feel, and the torque I use is likely much higher than 9, have never measured
it. I heat the head, and freeze the stub, and add Loctite RED just
before I assemble them, using a strap wrench or other tool.
Section 18-Exhaust system
Exhaust pipe finned nuts: Prior to 1981 the
specification was 101-130 foot-pounds, later it went to 145-159 foot-pounds,
and I have seen even higher published figures. There
is NO GOOD REASON to have these nuts too tight. I don't know how
tight I put them, but I suspect it is not over 100
foot-pounds. I never do them with a torque wrench, I always do it by feel, a
decent grunt, using a
proper finned wrench, and NOT too
darn tight,.......and I ALWAYS use
antiseize compound. Failure to loosen these nuts and to clean and
use fresh anti-seize compound on the threads yearly (I do it to the
rings, etc....and the rings have their splits towards the head, that is, the tapers face each other) has been
the cause for MUCH anguish. If, in loosening, they suddenly
bind-up, then do NOT go further with trying to loosen...just CUT the nuts
off!...don't injure threads doing so....
This having to cut them off, or ruining the threads, will NOT happen if you maintain
them, and do not overtighten them!!! there is an article on
this website, Exhaustnuts
on these finned nuts! Use of a quality antiseize is MANDATORY!!!
Exhaust system
'clips'....pre-silencer (1985+) 15 foot-pounds
Section 21-23 Clutch and transmission
Transmission drain: 14-18.5 foot pounds
Transmission fill: 20-22 foot pounds
Transmission to engine: about 15 foot-pounds, somewhat
more is OK. Books will show values from 14-24 depending
on the book (1981+ is 24
foot-pounds)....and some confused Nm
with foot-pounds.
Transmission shifter lever: 13 foot-pounds
Transmission cover screws: 6 foot-pounds
Transmission output flange-to-U-joint: 29 foot-pounds.
This requires an adapter tool of some sort. These bolts are
sturdy and strong, and a good feeling
of 'tight' from a common 6" 12 point box end wrench is probably OK.
Transmission output flange center large nut: 148-173
foot-pounds, probably OK to even 190.....in any case,
absolutely clean and dry.....and do
not clean with gasoline. I use 160. TAPER FITS must be CLEAN.
Kickstarter models cotter nut/crank: 15 foot-pounds
4 speed transmission shift fork bolts: 17 foot-pounds
Clutch lever adjusting screw locknut: 15 foot-pounds
Clutch bolts (to flywheel, early models): 16 or 17 foot-pounds in
books up to 1980. Originally the /5 had 14. From 1981
with the new style clutch, 15-16
foot-pounds.
Selector fork/cam bracket: 18 foot-pounds (from 1981,
14 foot-pounds)
Section 26-Driveshaft and swing arm
Driveshaft fill: 10 MAXIMUM foot pounds
Driveshaft drain: 10-12 MAXIMUM foot pounds
NOTE!....I almost
never actually use a torque wrench on the drain and fill and inspection
holes. This is particularly so on the driveshaft drain; and MOST
particularly so on the later drives that have the oil level inspection plug at
the rear of the drive....it is very easy to strip the threads, even if using a
torque wrench. There is NO need for those to be overly tight.
Please use any listed torque values with some common sense. NOTE that the
later rear drive type inspection plug torque is not listed on my website, on
purpose!
4 Driveshaft U-joint bolts, non-Paralever models: 29
foot pounds, NO lockwashers, and use Loctite
BLUE on clean and
dry threads. If you have the lockwashers, get rid of them, and use the
shorter later bolts. Early models like the
/5 were specified at 18 foot-pounds, that was the longer bolts with the
split lockwashers. I feel NO bike should have those long
bolts and those lockwashers, the 18 foot-pounds is listed here as a courtesy. If
one of those lockwashers breaks, or
somehow its bolt loosens, the rest soon will, and MAY destroy the back side of
the transmission. If your BMW dealer insists that BMW has gone back
to using lockwashers, ignore that advice, and use the shorter, later,
bolts!!!! Do NOT substitute bolts! Do NOT use hardware store bolts!
Driveshaft coupling nut (bell gear): 180 foot-pounds is
the maximum and probably 150 is OK.
Swing arm allen-recess adjusters: preload to 15
foot-pounds, then back off slightly, then finish in only the
tightening direction, leaving at 7.5
to 9 foot-pounds.
Swing arm adjuster 27 mm (or 1-1/16") lock nuts:
72-77 foot-pounds
Paralever:
Preloading the pivot shafts:
15 foot-pounds
then, back
off, then retighten to 7.5 foot-pounds; locknuts to 75-80 foot-pounds
Left-hand bearing pivot
stub:110 foot-pounds
Right-hand bearing pivot
shaft: 5.5 foot-pounds
Right-hand bearing pivot
shaft lock nut: 77 foot-pounds
Section 31/32-Steering, forks, bars, controls on bars
Special note: There
are differences between various models ...particularly the GS, -R, that are not
shown here, or the list would be very lengthy.
Fork drain nuts 16.6-18.6 foot pounds. Probably
one should just use 17 foot pounds for all to 1980.
Top cap nut, center tube, also called Crown Nut and Centering
Nut:
approximately 80-95 foot-pounds;
some books say 88-96
foot-pounds.
Top of fork tubes 'nut': 80 or so foot-pounds.
R80R, R100R, GS, top sleeve/locknut: 48 foot-pounds
There is a M8 x 1 nut at the bottom of some forks, that holds
the damper. Use about 15-17 foot-pounds.
Top spring retainer: 80-95 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) on early bikes 17 foot-pounds: 1981 and later 25
foot-pounds
Piston plugs: 18 foot-pounds
Damper slider tube, and force brace, 1985+: 11
foot-pounds
Axle clamp 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 footpounds
Fender brace, lower: 1.5-1.8 foot pounds
Fork brace, GS: 13 foot-pounds
Fork filler plugs: Various with models: 6.5-10
foot-pounds
Handlebar nuts: 15 foot-pounds
Steering bearing:
Whilst this should be done by road test, per my instructions elsewhere's, 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. It is
tricky.
Section 33-Rear Drive and rear shock absorbers
Rear drive drain: 16 foot pounds (18 maximum)
Rear drive fill: 20 foot pounds.
late model rear drive oil level inspection hole: CAREFULL!: 5
to 8 foot pounds
NOTE!....I almost
never actually use a torque wrench on the drain and fill and inspection
holes. This is particularly so on the driveshaft drain; and MOST
particularly so on the later drives that have the oil level inspection plug at
the rear of the drive....it is very easy to strip the threads, even if using a
torque wrench. There is NO need for those to be overly tight.
Please use any listed torque values with some common sense. NOTE that the
later rear drive type inspection plug torque is not listed elsewhere's on my
website, on purpose!..I NEVER use a torque wrench on them!
Rear drive to driveshaft housing: 35 MAXIMUM
foot-pounds
Shock absorbers: 25 foot-pounds; generally 1985+, 11
foot-pounds.
Shock units, Paralever: 26
foot-pounds
Shock units, Monolever before
1987: 34 foot-pounds; then 21 foot-pounds
Input gear (pinion) large nut, Loctite blue: /5/6 75
foot-pounds, later, 115
foot-pounds
The threaded ring that surrounds that input gear: 75
foot-pounds
Left side cover plate on the rear drive: 14 foot-pounds
12 sided bolts used on the drive from 1981: 43
foot-pounds (I have some reservations here)
Torque arm, front to frame: 32 foot-pounds
Torque arm, rear to housing: 25 foot-pounds
Bevel drive pinion retaining nut, R80GS, R80R, R100GS,
R100R: 150 foot-pounds
cover housing: 15 foot-pounds
oil filler/level plug: 17
foot-pounds
oil drain plug: 17 foot-pounds
Section 34-Brakes
Brake caliper plugs 43.3-46.6 foot pounds to 1980
Brembo calipers (and ATE that are NON-swinging): Book says 22-23 foot pounds
(ST, G/S 26) 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)
Cap (ATE swinging calipers): /6 45 foot-pounds;
/7 30 foot-pounds
Disc brake mounting nuts/bolts: 17 foot-pounds
for R80GS, R80R, R100GS, R100R:
24 foot-pounds
Section 36-Wheels and axles (and see section 31/32, above)
Front and rear axle nuts 32.5-34.5 foot pounds.
Axle pinch bolts, front 11-12 foot pounds, rear 11-13 foot pounds;
late 1984+
use 17 foot pounds both.
**NOTE....whilst those are published including 1984, I think the 1984 should really be
late 1984 and later, that is, models
that have the ball bearings in the
front axle, not the tapered bearings. I am NOT sure about this.
Mono-lever models, including R80ST, R80 G/S, rear wheel
bolts: Models have been made with both three and four
bolts/nuts.
I suggest
that one NEVER oil NOR antiseize these...NEVER!....just clean and dry
threads...and that you use 63 foot-pounds for the R80ST,
and a bit more, perhaps 75 for the G/S, and for the 85+ models, I suggest 77 foot-pounds.
Repeat: do NOT use oil, nor antiseize, on rear wheel-to-drive fasteners, on the models that are monoshock.
Section 46-to ? Frame, fenders, braces, saddlebag bracketry,
fairings, special lighting equipment, battery bracketry, instruments pods,
centerstands, etc.
Center stand: 25-26 foot pounds (I suggest closer to 31
on 1985+ models)
Sidestand center pin, from 1981: 13 foot-pounds
Rear subframe: 11-18 foot-pounds
***************
The
above information is tentative, not yet completely edited, so be cautious.
What is posted here IS believed correct, but no guarantees as to that!
You can have your torque wrench calibrated now and then, usually expensively, or simply clamp the square drive working end in a vice, have the handle horizontal, and place a weight on a string hanging from the point-of-pressure at the handle (mid-point of handle), and calculate the foot pounds. Carefully done, this is USUALLY OK.
Revised:
Initial edit and 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