33–01 Knuckle Pin Lubricating
Hold a pressure gun on each fitting until fresh grease
appears. See
or
. This will ensure that
all of the old contaminated grease has been forced
out. It is not necessary to exceed 4000 psi (27 560
kPa). The best distribution of new lubricant and the
best purging of old lubricant occurs when about 4000
psi (27 560 kPa) pressure is applied at the grease
gun nozzle. Using a 40 to 1 booster, the air should
be limited to 100 psi (689 kPa); using a 50 to 1
booster, the air should be limited to 80 psi (551 kPa).
Higher or lower pressures are not recommended.
When lubricating Meritor knuckle pin bushings or Alli-
ance Brand Product (ABP) axle needle bearings for
Initial Maintenance, raise the front axle until the front
tires are off of the ground. Wipe the lube fittings
clean, and slowly feed (for Meritor axles) multipur-
pose chassis grease (NLGI grade 1 or 2) into each
bushing area, or (for ABP axles), lithium 12-hydroxy
stearate (with molybdenum disulfide) WL grade 2
grease into each needle bearing area, while turning
the wheels from extreme right to left and back again
(lock-to-lock). This will eliminate small air pockets
and improve grease distribution.
Lower the front axle so that the tires are on the
ground, and regrease both top and bottom bushings
or needle bearings until new grease is seen at the
seal on the bushing or needle bearing opposite the
fittings.
NOTE: The grease seal will accept the grease
pressure without damaging the seal, and is de-
signed to have grease pumped out through it
during lubrication. Even if grease leaks out
around the top or bottom plate, continue pump-
ing until new grease is seen at the seal on the
bushing or needle bearing opposite the grease
fitting.
When lubricating knuckle pin bushings or needle
bearings at M1 through M3, do not raise the front
axle. Wipe the lube fittings clean, and (for Meritor
axles) apply multipurpose chassis grease, or (for
ABP axles), lithium 12-hydroxy stearate (with molyb-
denum disulfide) WL grade 2 grease, until new
grease is seen at the grease seal on the bushing or
needle bearing opposite the fittings.
33–02 Tie-Rod End Lubricating
Wipe the tie-rod end grease fittings clean, then (for
Meritor axles) pump multipurpose chassis grease
(NLGI grade 1 or 2), or (for ABP axles), lithium 12-
hydroxy stearate (with molybdenum disulfide) WL
grade 2 grease, to the tie-rod ends until all used
grease is forced out and new grease appears at the
ball stud neck.
f320032a
1
1
A
10/20/93
Pump lubricant into each grease fitting until fresh grease
comes out at A.
1.
Grease Fitting
Fig. 1, Meritor Axle Grease Fittings
06/13/2003
f330213
1
1
2
1.
Grease Fitting
2.
Steering Knuckle
Fig. 2, ABP Axle Grease Fittings
Front Axle
33
School Bus Chassis Maintenance Manual, July 2003
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