Pinion Installation - GMC T Series 1994 Repair Manual

• Set the dial indicator at ZERO, then position it
in J 33838. Push the dial indicator downward
until the needle rotates approximately 3/4 turns
to the right.
4. Tighten the dial indicator in this position.
5. Set the button of J 33838 on the differential bear­
ing bore (figure 19).
6. Rotate the tool slowly back and forth until the dial
indicator reads the lowest point of the bore. Set the
dial indicator to ZERO. Repeat the rocking action
of the tool to verify the ZERO setting.
7. After the ZERO setting is obtained and verified,
move the tool button out of the differential side
bearing bore (figure 19). Record the dial indicator
reading.
8. The dial indicator reading is equal to the required
shim size.
Example: If the dial indicator reads 0.84 mm
(0.003 inch) in step 8, a 0.84 mm (0.003 inch) shim
is required. Available shim sizes are listed in
" Specifications."
9. Remove tools and bearing cones.
PIN IO N INSTALLATION
Install or Connect (Figure 1, 2, 10, 20 and 21)
Tools Required:
J 33785 Bearing Installer
J 8614-01 Pinion Flange Remover
J 33792 Seal Installer
1. Shim (38) to the pinion gear (37).
• The shim must be of the proper size, as select­
ed previously.
2. Bearing (39) onto the pinion gear (37) using
J 33785 (figure 20).
3. New spacer (40) onto the pinion gear (37).
4. Bearing (41) into the case.
5. Seal (42) into the case using J 33782 (figure 21).
6. Pinion gear, with bearing and spacer, to the case.
7. Deflector (43), flange (44), washer (45) and nut (46).
A. Apply PST sealant (GM P/N 1052080) or equiv­
alent to the pinion gear threads and on both
sides of the washer.
B. Tighten nut (46) until no end play is detectable
while holding the flange (44) with J 8614-01
(figure 10).
C. No further tightening should be attempted until
bearing preload has been checked.
Measure
*
• Pinion bearing preload. Use an inch-pound torque
wrench (figure 22).
•T h e correct preload is 1.7-2.8 N-m (15-25 lbs. in.).
1. Rotate the pinion with the torque wrench and
observe the reading.
2. If the preload torque is below specifications, contin­
ue torquing the pinion nut in small increments.
Check the preload after each tightening. Each tight­
ening increases the bearing preload by several
inch pounds. If the bearing preload is exceeded,
the pinion will have to be removed, and a new
collapsible spacer installed.
3. Once the preload has been obtained rotate the pin­
ion several times to make sure that the bearings
have seated. Recheck the preload, and adjust if
necessary.