GMC 1990 Light Truck Repair Manual page 155

Figure 19—Installing the Side Bearing
• Service shims are available from 0.040 to 0.100-inch.
• Be sure that the side bearing surfaces are clean and
free of burrs.
Tool Required:
J 22779 Side Bearing Backlash Gage
1. Place the differential case and the bearing cups into
the axle housing.
• Lubricate the axle bearings with axle
lubricant.
• Support the case to keep it from falling into the
axle housing.
2. Install the strap from J 22779 on the left bearing with
the cap bolts. Tighten the bolts snugly.
3. Push the ring gear towards the pinion.
• Engage the ring gear with the pinion tightly, to
a backlash of 0.000 to 0.001-inch.
4. Insert J 22779 between the axle housing and the left
bearing cup (figure 20).
5. Move the tool back and forth in the bore while
turning the adjusting nut to the right until a
noticeable drag is produced (figure 21).
• Tighten the lock bolt on the side of the tool.
Figure 20—Installing Side Bearing Gaging Tool
8 2
V -INCH RING GEAR 4B2-9
Figure 21—Measuring Side Bearing Shim
Requirements
• Leave the tool in place.
6. Install a service spacer (9) and a service shim (9)
between the right bearing cup and the axle housing.
7. D eterm ine bearin g
progressively larger feeler gage sizes between the
carrier and the service shim.
• Push the feeler gage downward so that it
contacts the shim at the top and bottom, and
then contacts the axle housing.
• The point just before additional drag begins is
the correct feeler gage thickness. This is the
zero setting without preload.
8. Remove the strap, J 22779, the service spacer,
service shim, feeler gage, and differential case from
the axle housing.
9. M easure J 22779 in three places using a
micrometer. Average the readings (figure 22).
10. Add the dimensions of the right side service spacer,
service shim, and the feeler gage.
Figure 22—Measuring the Gage Plate Thickness
preload by in se rtin g