Inspection Before Disassembly

The differential case assembly and drive pinion should be inspected before they are removed from the carrier casting. These inspections can find the cause of the concern and determine the resolution.

1. Wipe the lubricant from the internal working parts and visually inspect the parts for wear and/or damage.

2. Rotate the gears to see if there is any roughness which would indicate damaged bearings or gears.

Checking Ring Gear Backface Runout:

3. Check the ring gear teeth for signs of scoring, abnormal wear or nicks/chips.

4. Set up a dial indicator and check ring gear backlash and ring gear backface runout. Backlash should be 0.008 inch to 0.015 inch (0.012-0.015 inch preferred). To check ring gear backface runout, mount Dial Indicator with Bracketry, TOOL-4201 -C, or equivalent on the carrier so the tip of the dial indicator contacts the backface of the ring gear. Back face runout should be no more than 0.101mm (0.004 inch).

NOTE: There is a space provided between the excitor ring and the ring gear for measuring ring gear backface runout.

Checking Ring Gear For Backlash:

5. A contact pattern is not an acceptable guide to check for noise. Proper gear set assembly must be checked using the Rear Axle Pinion Depth Gauge Tool set which shows the correct pinion shim required to assure acceptable running condition. See section on Drive Pinion and Gear Set.