GMC 1990 Light Truck Repair Manual page 225

• Press the bearings on using a suitable tool.
DIFFERENTIAL INSTALLATION
|-»<-| Install or Connect
1. Bearing cups (33) to the carrier (36).
2. Adjusting nuts (32).
3. Bearing caps (25).
4. Cap bolts (23).
Tighten
• Bolts to 176 N m (130 ft. lbs.).
The bearing cups must have a hand fit in the
bearing bores: If the fit is too tight, rework the bore
with emery cloth, until a hand fit is obtained (figure
23).
Remove or Disconnect
1
. Cap bolts (23).
2. Bearing caps (25).
3. Adjusting nuts (32).
4. Bearing cups (33).
0
Install or Connect
• Lubricate all parts with axle lubricant.
1. Bearing cups (33) onto the bearings.
2. Differential assembly (36) to the carrier.
3. Bearing adjusting nuts (32).
• Turn the nuts hand-tight against the bearing
cups.
4. Bearing caps (25) (figure 24).
• Tap lightly into position.
5. Cap bolts (23).
Tighten
• Bolts to 176 N-m (130 ft. lbs.).
CHECKING RING GEAR RUN OUT
Measure
1
. Ring gear run out.
• Mount a dial indicator to the carrier. The dial
indicator stem should rest on the back face of
the ring gear.
• Loosen the adjusting nut opposite the ring
gear enough to notice end play on the
indicator.
• Tighten the same adjusting nut just enough to
0 000
have . -inch end play on the indicator.
• Rotate the gear, and check for run out. If the
run out exceeds 0.008-inch, remove the
differential, and determine the cause.
BACKLASH ADJUSTMENT
• The differential side bearing preload is adjusted by
two adjusting nuts in the differential bearing bore.
The bore and the bearing cap provide the mating
threads for the bearing nut.
• The differential must be initially preloaded in order
to determine the backlash of the gear set. After the
backlash has been set, the final bearing preload is
set.
12-INCH RING GEAR (ROCKWELL) 4B6-9
Adjust
1
. The bearing preload by tightening the adjusting nuts
(32) one notch each from 0.000 end play. Refer to
"Checking Ring Gear Run Out" (figure 25).
• Mount a dial indicator to the carrier (46). Place the
stem of the indicator onto the toe end of a tooth
(figure 26).
2. Backlash by moving the ring gear toward or away
from the pinion.
• If setting up the original ring and pinion gear
set, use the backlash reading obtained earlier.
• Set the backlash to 0.005 - 0.015-inch for new
gear sets.
• If the backlash is too high, move the ring gear
toward the pinion.
• If the backlash is too low, move the ring gear
away from the pinion.