Ford Mustang (1999-2004) Service Manual: Installation

1. Inspect the pinion flange seal journal for rust, nicks, and scratches prior to installing the flange.

Polish the seal journal with fine crocus cloth, if necessary.

2. Lubricate the pinion flange splines.

• Use SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL or equivalent meeting Ford specification WSP-M2C197-A.

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

Position the pinion flange.

4. Using the special tools, install the pinion flange.

5. CAUTION: Do not under any circumstance loosen the nut to reduce preload. If it is necessary to reduce preload, install a new collapsible spacer (4662) and nut.

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

Tighten the nut to set the preload.

• Rotate the drive pinion occasionally to make sure the differential pinion bearings (4630) (4621) seat correctly. Take frequent differential pinion bearing torque preload readings by rotating the drive pinion with a Nm (inch/pound) torque wrench.
• If the preload recorded prior to disassembly is lower than the specification for used bearings, then tighten the nut to specification. If the preload recorded prior to disassembly is higher than the specification for used bearings, then tighten the nut to the original reading as recorded.
• Refer to the torque specification for used differential pinion bearings in the Specifications portion of this section.

6. CAUTION: Align the index marks.

CAUTION: The driveshaft centering socket 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.

Connect the driveshaft.

7. Install the rear brake calipers.

8. Install the rear wheel and tire assemblies.

9. Lower the vehicle.