Ford 8.8-Inch IRS

Special Tools:

Removal
1. Raise and support the vehicle.
2. Remove the rear wheel and tire assemblies.

3. CAUTION: Remove the brake drums to prevent brake drag during drive pinion bearing preload adjustment.

Remove the brake drums.





4. Mark the driveshaft flange and pinion flange for correct alignment during installation.





5. Remove the four driveshaft bolts and disconnect the driveshaft.
- Wire the driveshaft out of the way.





6. Install a Nm (inch-pound) torque wrench on the pinion nut and record the torque required to maintain rotation of the pinion through several revolutions.

7. CAUTION: After removal of the pinion nut, discard it. A new nut must be used for installation.





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





8. Mark the driveshaft pinion flange in relation to the drive pinion stem to make sure of correct alignment during installation.





9. Using the special tool, remove the pinion flange.

Installation
1. Lubricate the pinion flange splines.
- Use Motorcraft Synthetic Rear Axle Lubricant F1TZ-19580-B or equivalent meeting Ford specification WSL-M2Cl 92-A.

2. Note: Disregard the scribe marks if a new pinion flange is being installed.





Align the pinion flange with the drive pinion shaft.





3. With the drive pinion in place in the rear axle housing, install the pinion flange using the special tool.





4. Position the new pinion nut.

5. CAUTION: Under no circumstances is the pinion nut to be backed off to reduce preload. If reduced preload is required, a new collapsible spacer and pinion nut must be installed.





Using the special tool to hold the pinion flange, tighten the pinion nut.
- Rotate the pinion occasionally to make sure the cone and roller bearings are seating correctly.
- Install a Nm (inch-pound) torque wrench on the pinion nut.
- Rotating the pinion through several revolutions, take frequent cone and roller bearing torque preload readings until the original recorded preload reading is obtained.
- If the original recorded preload is lower than specifications, tighten to the appropriate specifications for used bearings. If the preload is higher than specification, tighten the nut to the original reading as recorded.





6. Position the rear driveshaft and align the marks on the pinion flange.





7. Install the four driveshaft pinion flange bolts.
8. Install the brake drums.
9. Install the rear wheel and tire assemblies.