Backlash & Final Assembly
WARNING: This page does not describe the selected car, but rather 20 other vehicles, including the 1990 GMC Vandura Special, 1990 GMC Vandura, 1990 GMC Safari, 1990 GMC S15 Pickup, and 1990 GMC S15 Jimmy. However, it is still accessible from the selected car via links, so may be relevant.
- Rotate case several times to seat bearings. Check backlash at 4 locations around outside edge of ring gear using a dial indicator mounted to axle housing. Install indicator in line with gear rotation and perpendicular to tooth angle. Pinion must be held steady while taking readings. Variation should not exceed .002" (.05 mm).
- If backlash is incorrect, adjust side bearing shims as necessary. After adjustment is completed, make a tooth contact pattern test and make any necessary corrections. Install axle shafts and housing cover. See Fig 1 .
NOTE:
Total shim pack thickness for right and left side combined must not be changed. If a shim is removed from one side, same thickness shim must be added to other side.
AXLE ASSEMBLY SPECIFICATIONS
| Application | Specifications: In. (mm) | ||
|---|---|---|---|
| Ring Gear Backlash | .005-.009 (.13-.23) | ||
| Side Bearing Preload | .008 (.20) | ||
| INCH Lbs. (N.m) | |||
| Pinion Bearing Preload | |||
| 7 1/2" & 7 5/8" Ring Gear | |||
| Used Bearings | 8-12 (1.0-1.4) | ||
| New Bearings | 24-32 (2.7-3.6) | ||
| 8 1/2" & 9 1/2" Ring Gear | |||
| Used Bearings | 10-15 (1.1-1.7) | ||
| New Bearings | 20-25 (2.3-2.8) | ||