Assembling The Differential Into The Axle Housing; Checking Backlash - GMC T Series 1994 Repair Manual

Figure 28— Measuring Backlash
ASSEMBLING THE DIFFERENTIAL INTO THE AXLE
HOUSING
Tools Required:
J 8092 Driver Handle
J 23690 Differential Side Bearing Installer
J 24385-01 Differential Carrier Spreader
1. Force the ring gear into mesh with the pinion. Rock
the ring gear to allow the teeth of the gears to
mesh.
2. Assemble the differential (22) with master bearings
installed to the axle. The pinion must be installed.
3. Mount a dial indicator having a minimum travel of 5
mm (0.200 inch) with a magnetic base on the ring
gear bolt side of the housing (figure 25).
4. Place the indicator tip on the chalk mark made
earlier.
5. With the force still applied to the differential case,
set the dial indicator to zero.
6. Force the differential case away from the pinion
gear to obtain an indicator reading. Repeat this
action until a consistent reading is obtained.
Record the reading.
7. Remove the indicator and the differential case from
the axle housing.
8. Remove the master bearings from the differential
case.
9. Using the total shim pack size determined earlier,
(Refer to " Determining Total Shim Pack Size" ) sub­
tract the reading found in step 6 from the total
reading. The reading found in step 6 will be the
shim size on the ring gear side. The remaining
portion of the shim pack will be used on the side
opposite the ring gear. Add an additional 0.25 mm
(0. 010 inch) of shims to the side opposite the ring
gear to preload the bearings.
10. Place the proper shims on the differential side
bearing hub (ring gear side) and drive the differen­
tial bearing onto the hub using J 8092 and J 23690
(figure 26).
11. Place the proper shims on the differential side
bearing hub (opposite the ring gear) and drive the
differential bearing onto the hub using J 8092 and
J 23690.
• If installing a new bearing, make sure it is the
same width as the old one.
12. Assemble J 24385-01 to the axle (figure 27).
13. Assemble the dial indicator. Preset the gage at
least.05 mm (0.020 inch), then rotate the indicator
housing to zero the dial.
NOTICE: Do not spread the axle housing
more than 0.38 mm (0.015 inch). Overspread­
ing can damage or distort the housing.
14. Spread the housing while examining the dial indi­
cator.
15. Remove the dial indicator.
16. Place the bearing cups (20) onto the bearings.
17. Install the differential assembly into the carrier.
• Use a soft-faced hammer to seat the differential
assembly in the axle housing.
18. Remove the spreader.
19. Install the bearing caps (18) in their original posi­
tions.
NOTICE: Refer to "Notice" on page 4B5-1.
20. Install the bearing cap bolts (19).
Tighten
• Bolts (19) to 115 N-m (85 lbs. ft.).

CHECKING BACKLASH

1. Mount a dial indicator with a magnetic base to the
axle housing (figure 28).
2. Place the indicator tip at the heel end of the tooth.
3. Check the backlash at three equally spaced points.
T h e b a c k la s h s h o u ld
(0.005-0.009 inch). The measurement must not
vary more than 0.05 mm (0.002 inch) between the
points checked.
A. High backlash is corrected by moving the ring
gear closer to the pinion.
B. Low backlash is corrected by moving the ring
gear away from the pinion.
be 0 . 1 3 - 0 . 2 3 mm