Test Procedure

WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Using the appropriate cleaning solvent, remove the lubricant from the differential housing and from the teeth of the ring gear.

Fig 1: Applying Gear Marking Compound To Ring Gear Teeth

Courtesy of GENERAL MOTORS CORP.

Using a medium stiff brush, sparingly apply gear marking compound to all of the ring gear teeth. Refer to Adhesives, Fluids, Lubricants, and Sealers .

CAUTION: Refer to Fastener Caution .

Torque the differential bearing caps.
- Tighten the differential bearing caps. For the 8.6 inch axle, tighten the bearing caps to 75 N.m (55 lb ft)
- For the 9.5 inch LD axle, tighten the bearing caps to 95 N.m (63 lb ft)
- For the 10.5 inch axle, tighten the bearing caps to 185 N.m (136 lb ft)
Apply the park brake until the torque load is 14 N.m (10 lb ft) is required to rotate the pinion.

NOTE: Avoid rotating the ring gear excessively, this could give a false contact pattern.

Using the appropriate size wrench, slowly rotate the drive pinion flange/yoke 3 complete revolutions clockwise.
Slowly rotate the drive pinion flange/yoke 3 complete revolutions counter-clockwise.
Observe the contact pattern on the teeth. Refer to Gear Tooth Contact Pattern Inspection .