Western Star 47X 2020, Maintenance Manual

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U-joints. If a low-pressure adapter is not used,
U-joints may not receive enough grease.
Using lithium 12-Hydroxy stearate grease (NLGI
Grade 2, with EP additives), lubricate until
new
grease can be seen at all four U-joint seals.
Fresh grease must be seen escaping from all
four bearing-cap seals of each U-joint. On full-
round yokes equipped with a bearing cup, if most
of the grease being added to a U-joint can be
seen escaping from just one of the U-joint seals,
check the torque on the capscrews at that seal.
4. Tighten the bearing-cup capscrews 43 lbf·ft (58
N·m). If the capscrews were already tight, or all
of the U-joint seals still do not purge, remove the
bearing cup at that seal, and examine the seal
for damage. If the seal is damaged, replace the
complete U-joint.
5. If grease does not appear at one seal, use a pry-
ing tool to pry the U-joint trunnion away from the
non-purging seal, or tap the driveshaft or yoke
with a plastic or rawhide mallet on the side oppo-
site the dry seal, while continuing to lubricate. If
grease still does not appear, loosen the cap-
screws at the bearing with the dry seal, to relieve
seal tension. Lubricate the U-joint until new
grease is seen at the seal, then tighten the cap-
screws to the correct torque specifications. If the
bearing will not take grease, replace the U-joint.
Refer to
Group 41 of the 47X and 49X Work-
shop Manual for replacement instructions.
6. Check the purged grease. If it appears rusty,
gritty, or burned, replace the U-joint.
7. Wipe the purged grease from the seals, and any
excess grease from the grease fitting.
Slip Joint Spline Lubrication
NOTE: Vehicles equipped with Meritor RPL Se-
ries drivelines do not require periodic lubrication.
1. If equipped with a grease fitting, wipe all old
grease and dirt from the slip joint grease fitting.
See
Fig. 6 .
2. Use a hand-type grease gun or a high-pressure
gun with a low-pressure adapter, to lubricate the
slip joint. Add multipurpose chassis grease
(lithium 12-hydroxy stearate, NLGI Grade 2, with
EP additives) until it appears at the pressure-
relief hole in the yoke plug. Then cover the relief
hole with your finger, while continuing to apply
gun pressure until new grease appears at the
slip joint seal. See
Fig. 6 . This ensures complete
lubrication of the splines.
3. Wipe the purged grease from the pressure-relief
hole and slip joint seal, and any excess grease
from the grease fitting.
Driveline
41
47X and 49X Maintenance Manual, August 2020
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