C 1500 Truck 2WD V8-393 6.5L DSL Turbo VIN S (1996)
being reused, backlash should be adjusted as close as possible to value measured prior to disassembly.
9.
Backlash is adjusted by increasing thickness of one shim while decreasing thickness of opposite side shim by the same amount in order to maintain
proper side bearing preload. Select shims to adjust backlash as follows:
a. If backlash is excessive, decrease thickness of shim on gear tooth side and increase thickness of shim on opposite side by the same amount.
b. If backlash is less than specified, increase thickness of shim on gear tooth side while decreasing thickness of opposite shim by the same
amount.
On models with 7-1/2 & 7-5/8 inch ring gear, each .002 inch change in shim thickness alters backlash by .001 inch. On models
with 8-1/2 and 8-5/8 inch ring gear, each .003 inch change in shim thickness alters backlash by .002 inch.
10.
Reinstall differential assembly, shims and bearing caps, torque bearing cap bolts to 55 ft. lbs., then recheck backlash and adjust as needed.
11.
If side bearing preload was set to zero during side bearing preload adjustment, proceed as follows:
a. Remove both bearing caps and shim packs, keeping shim packs in respective left or right positions.
b. Select shim .004 inch thicker than one removed from left side, insert shim between left bearing race and spacer, then install left bearing cap
with bolts hand tight.
c. Select shim .004 inch thicker than one removed from right side and install shim between right bearing race and spacer using suitable driver.
d. Install right bearing cap and torque all cap bolts to 55 ft. lbs.
12.
Ensure that ring gear teeth are clean and free from oil, then coat both drive and coast side of each tooth with suitable marking compound.
13.
Apply braking force to ``load'' ring gear, then rotate driveshaft yoke with wrench so that ring gear rotates one full revolution in each direction.
Test
made without ``loading'' gears will not yield satisfactory pattern, and excessive rotating of gears is not recommended.
14.
Compare gear tooth pattern with
Fig. 19, and correct assembly adjustments as needed.
15.
When proper gear tooth contact pattern has been obtained, clean marking compound from gears, install cover and new gasket and fill housing with
specified lubricant.
Side Bearing Preload & Backlash
On these models, side bearing preload should be set before pinion is installed. If pinion is installed, remove ring gear.
1. Ensure bearing bores in housing and bearing caps are clean and free from burrs.
2. Measure production shims or service spacer and shim packs removed during disassembling to determine approximate thickness of shims needed
for installation.
Do not reuse cast iron production shims as they may break during installation. If service spacers and shims were
previously installed, they can be reused.
Fig. 12 Side Bearing Shim Selection Chart. Models W/7 1/2 & 7 5/8 Inch Ring Gear.
3. In addition to 0.170 inch service spacers for each side, refer to chart,
Fig. 12, and select service shim thickness required based on measurements
made in step 2.
4. Place outer races over side bearings, mount differential assembly in housing and insert service spacer between each bearing race and housing with
chamfered edge against housing.
5. Install left bearing cap to retain case assembly and tighten bolts hand tight so that case can be moved while checking adjustments.
A bearing cap
bolt can be installed in lower right bearing cap hole to prevent case from dropping while performing shim adjustments.
6. Select one or two shims totaling thickness calculated in step 3 and insert shims between right bearing cap and service spacer.
