Checking Backlash; Final Assembly - GMC 1989 Light Duty Truck Repair Manual

4C2-14 9 /4-INCH RING GEAR FRONT AXLE
3
• Use a rawhide hammer to seat the differential
assembly in the axle housing (figure 40).
18. Remove the spreader.
19. Install the bearing caps (18) in th e ir origin al
positions.
20. Install the bearing cap bolts (19).
T ig h ten
» Bearing cap bolts (19) to 115 N m (85 ft. lbs.).

CHECKING BACKLASH

1. Mount a dial indicator with a magnetic base to the
axle housing as shown in figure 41.
2. Place the indicator tip at the heel end of the tooth.
3. Check the backlash at three equally spaced points.
The backlash should be 0.13 - 0.23 mm (0.005 -
0.009-inch). The measurement must not vary more
than 0.05 mm (0.002-inch) between the points
checked.
Figure 4 0 — Installing th e D ifferen tial Case
4. High backlash is corrected by moving the ring gear
closer to the pinion.
5. Low backlash is corrected by moving the ring gear
away from the pinion.
6. To adjust the backlash, the differential case must be
removed from the housing, then the differential
bearings removed, and the proper number of shims
moved from one side to the other.

FINAL ASSEMBLY

Install or C onnect (Figure 1)
1. Drive axles, as outlined in the proper Light Duty
Truck Service Manual.
2. Axle cover (14) to the housing.
• Make sure the sealing surfaces on the cover
and housing are clean and free of grease and
oil.
• Apply a bead of RTV sealer (GM part no.
1052366 or equivalent) to the cover, inboard of
the bolt holes. Install the cover while the
sealer is still wet.
3. Cover bolts (17).
Tighten
Bolts to 47 N m (35 ft. lbs.).