21 2 MA1 NTENANCE-CHASSIS
end pivots on a shaft connected to the frame.
the rear wheel receives a shock, the swing arm, pivoting
on its shaft, allows the wheel to move up and down in
relation to the frame within the limits o f the shock
This motorcycle has needle bearings at the swing
I f bearing wear has progressed such that
the swing arm has become loose, the motorcycle will
be unstable. To minimize wear, the swing arm should
be kept properly lubricated.
A bent pivot shaft or twisted swing arm will also
cause instability by throwing the rear wheel out of
A bent pivot shaft may also cause bearing
Swing arm bearing wear
Measure the outside diameter o f the swing arm
sleeve at both ends with a micrometer.
swing arm sleeve if the diameter
less than the service
limit or i f i t shows visible damage.
A. Swing Arm Sleeve
Swing Arm Sleeve
The rollers in the needle bearings wear so little that
the wear is difficult to measure.
Instead, inspect the
needle bearings for abrasions, color change, or other
I f there is any doubt as to its the condition
o f either needle bearing, replace both needle bearings.
Whenever the swing arm sleeve i s replaced, also replace
the needle bearings.
Swing arm lubrication
There is a grease nipple on the swing arm for lubri-
Grease the swing arm with regular cup grease
as a part o f general lubrication (Pg. 3 3 ) with the fre-
quency given in the Periodic Maintenance Chart (Pg.
10). Force the grease into the nipple until i t comes
out at both sides o f the swing arm, and wipe off any
I f the grease does not come out, first check
that the nipple is not clogged with dirt or old grease.
I f the nipple it clear but still will not take grease; re-
move the swing arm (Pg. 1
pull out the sleeve, clean
out the old grease, and apply grease to the needle
To measure the pivot shaft runout, set the pivot shaft
on V blocks at the end o f the pivot shaft, and set a dial
gauge to the shaft halfway between the blocks. Turn the
shaft to measure the runout.
The amount of runout
is the amount o f dial variation.
I f the shaft runout
exceeds the service limit, straighten it.
I f i t cannot
be straightened, or i f the runout exceeds the repair
limit, replace the shaft.
Pivot Shaft Runout
A. Grease Nipple
A. Needle Bearing
Pivot Shaft Runout