Backlash Adjustment - GMC T Series 1994 Repair Manual

4.32 MM (0.170-INCH) SERVICE SPACER
Total Thickness of
Both Prod. Shims
Removed
10.57 mm (0.420- nch)
10.92 mm (0.430- nch)
11.18 mm (0.440- nch)
11.43 mm (0.450- nch)
11.68 mm (0.460- nch)
11.94 mm (0.470- nch)
12.19 mm (0.480- nch)
12.45 mm (0.490- nch)
12.70 mm (0.500- nch)
12.95 mm (0.510- nch)
13.21 mm (0.520- nch)
13.46 mm (0.530- nch)
13.97 mm (0.550- nch)
Figure 21— Shim Thickness Chart
1. The pinion inner bearing using J 5590 (figure 22).
• Drive the bearing on until the cone seats on the
pinion shims.
2. A new collapsible spacer.
• Lubricate the pinion bearings with axle lubri­
cant.
3. Pinion to the axle housing.
4. Outer pinion bearing onto the pinion using J 5590.
Hold the pinion forward from inside the case
f
while driving the bearing onto the pinion.
5. Pinion oil seal using J 23911.
6. The pinion flange by tapping it with a soft-faced
hammer until a few threads show through the pin­
ion flange.
7. The pinion washer and nut while holding the pinion
flange with J 8614-01.
A. The nut until the pinion end play is just taken
up. Rotate the pinion while tightening the nut to
seat the bearings. Once there is no end play in
the pinio n, the preload to rq u e should be
checked.
20. Pinion
Total Thickness of
Service Shims To Be
Used As A Starting Point
1.52 mm (0.060- nch)
1.78 mm (0 070- nch)
2.03 mm (0.080- nch)
2.29 mm (0.090- nch)
2.54 mm (0.100- nch)
2.79 mm (0.110- nch)
3.05 mm (0.120- nch)
3.30 mm (0.130- nch)
3.56 mm (0.140- nch)
3.81 mm (0.150- nch)
4.06 mm (0.160- nch)
4.32 mm (0.170- nch)
4.83 mm (0.190- nch)
F4685
F4686
B. Remove J 8614-01. Using an inch-pound torque
wrench, check the pinion preload by rotating the
pinion with the wrench (figure 23). Preload
should be at or below 2.7 to 3.6 N-m (24 to 32
lbs. in.) on new bearings, or 1.0 to 1.4 N-m (8
to 12 lbs. in.) for used bearings.
C. If the preload torque is below the specified val­
ues, continue torquing the nut in small incre­
ments. Check the preload after each tightening.
Each tightening increases the bearing preload
by several pounds. If the bearing preload is
exceeded, the pinion will have to be removed,
and a new collapsible spacer installed.
D. Once a preload of 2.7 to 3.6 N-m (24 to 32 lbs.
in.) has been obtained, rotate the pinion several
times to ensure the bearings have seated.
Recheck the preload and adjust if necessary.
8. Differential case. Refer to "Backlash Adjustment."

BACKLASH ADJUSTMENT

NOTICE: For steps 5 and 13, refer to "Notice"
on page 4B1.
1. Install the differential case, bearing cups, spacers,
and shims as determined from the " Side Bearing
Preload Adjustment."
2. Rotate the case several times to seat the bearings.
3. Install a dial indicator to the case using a magnetic
base.
4. Place the indicator stem at the heel end of a tooth
(figure 24).
• Set the dial indicator so the stem is in line with
the gear rotation and perpendicular to the tooth
angle.