Rear Drive Axle/Differential

Drive Pinion Flange and Drive Pinion Seal

Special Tool(s):

Material:

Removal

CAUTION: Remove the rear wheel and tire assemblies, brake calipers and brake discs to prevent brake drag during the drive pinion bearing preload adjustment.

1. WARNING: The electrical power to the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the LH rear quarter trim panel. Failure to do so can result in unexpected inflation or deflation of the air springs, which can result in shifting of the vehicle during these operations. Failure to follow these instructions may result in personal injury and vehicle damage.

NOTE: If equipped, turn the air suspension switch to the OFF position.

With the vehicle in NEUTRAL, position the vehicle on a hoist.
2. Remove the rear wheel and tire assemblies.

3. CAUTION: Do not allow the brake caliper to hang from the brake hose. Provide a suitable support.

Remove the rear brake calipers and the brake discs. Position the brake calipers aside.
4. Remove the rear driveshaft assembly.
5. Install a Nm (lb-in) torque wrench on the nut and record the torque necessary to maintain rotation of the drive pinion gear through several revolutions.





6. CAUTION: After removing the pinion nut, discard it. Use a new nut for installation.

Use the special tool to hold the pinion flange while removing the pinion nut.





7. Index-mark the drive pinion flange and the drive pinion gear stem to maintain initial balance during installation.





8. Using the special tool, remove the drive pinion flange.





9. Force up on the metal flange of the drive pinion seal. Install gripping pliers and strike with a hammer until the pinion seal is removed.





Installation
1. Lubricate the lips of the new drive pinion seal with grease.

2. CAUTION: If the drive pinion seal becomes misaligned during installation, remove it and install a new seal.

Using the special tool, install the drive pinion seal.





3. Lubricate the drive pinion flange splines with rear axle lubricant.

4. NOTE: Disregard the index marks if installing a new drive pinion flange.

Position the drive pinion flange.





5. Using the special tool, install the drive pinion flange.





6. Position the new drive pinion nut.





7. CAUTION: Do not under any circumstance loosen the nut to reduce preload. If it is necessary to reduce preload, install a new drive pinion collapsible spacer and nut.

CAUTION: Remove the special tool while taking preload readings with the Nm (inch-pound) torque wrench.

Use the special tool to hold the pinion flange while tightening the nut.
^ Rotate the pinion occasionally to make sure the pinion bearings seat correctly. Take frequent pinion bearing torque preload readings by rotating the drive pinion gear with a Nm (lb-in) torque wrench.
^ If the preload recorded prior to disassembly is lower than the specification for used bearings, tighten the nut to specification. If the preload recorded prior to disassembly is higher than the specification for used bearings, tighten the nut to the original reading as recorded.
^ Refer to the torque specification for used pinion bearings.





8. CAUTION: Install the driveshaft with new bolts. If new bolts are not available, apply sealer to the threads of the original bolts.

CAUTION: Align the index marks.

CAUTION: The driveshaft flange yoke fits tightly on the pinion flange pilot. To make sure that the yoke seats squarely on the flange, tighten the bolts evenly in a cross pattern as shown.

Install the rear driveshaft.
9. Install the rear brake discs and the brake calipers.
10. Install the rear wheel and tire assemblies.
11. Lower the vehicle.
12. If equipped with air suspension, reactivate the system.