This service procedure disturbs the pinion bearing preload and this preload must be carefully reset when assembling.
- Raise the vehicle and support it safely.
- Drain the differential oil.
- Remove the wheels and the brake rotors.
- Mark the driveshaft and the axle companion flange so the driveshaft can be reinstalled in the same position. Remove the driveshaft.
- Using an inch pound torque wrench on the pinion nut, record the torque required to maintain rotation of the pinion through several revolutions.
- While holding the companion flange with a suitable tool, remove the pinion nut. Mark the companion flange in relation to the pinion shaft so the flange can be reinstalled in the same position.
- Using a 3-jawed puller tool or equivalent, remove the rear axle companion flange. Use a small prybar to remove the seal from the carrier.
- Make sure the splines of the pinion shaft are free of burrs.
- Apply grease to the lips of the pinion seal and install, using a seal installation tool.
- Check the seal surface of the companion flange for scratches, nicks or a groove. Replace the companion flange, as necessary. Apply a small amount of lubricant to the splines. Align the mark on the flange with the mark on the pinion shaft and install the companion flange.
The companion flange must never be hammered on or installed with power tools.
- Install a new nut on the pinion shaft. Hold the companion flange with a suitable tool while tightening the nut.
- Tighten the pinion nut, rotating the pinion occasionally to ensure proper bearing seating. Take frequent pinion bearing torque preload readings until the original recorded preload reading is obtained.
Under no circumstances should the pinion nut be backed off to reduce preload. If reduced preload is required, a new collapsible pinion spacer and pinion nut must be installed.
- Install the driveshaft and add the correct amount and type of differential fluid to the carrier. Lower the vehicle.
Removal & Installation
- Before servicing the vehicle, refer to the Precautions section.
- Index-mark the front driveshaft and pinion flange.
Remove or disconnect the following:
NOTEDo not allow the driveshaft to hang unsupported.
Front driveshaft from the pinion flange, and position it aside
- Using a Nm (inch-pound) torque wrench, measure the torque required to maintain pinion rotation. Record the measurement.
- Index-mark the pinion flange and the pinion stem.
- Hold the pinion flange while removing the nut.
- Place a drain pan under the differential housing.
- Using a puller, remove the pinion flange.
- Inspect the pinion flange for burrs and damage. Inspect the end of the pinion flange that contacts the bearing cone, the nut counterbore, and the seal surface for nicks. Discard the pinion flange as necessary.
- Using a seal remover and impact slide hammer, remove the pinion seal.
- Remove the front axle drive pinion shaft oil slinger and the differential pinion bearing.
Remove and discard the collapsible spacer.
- Verify that the splines on the pinion stem are free of burrs. If burrs are evident, remove them with a fine crocus cloth. Work in a rotating motion to wipe the pinion clean.
- Clean the pinion seal bore.
- Install a new collapsible spacer.
- Install the original differential pinion bearing and the front axle drive pinion shaft oil slinger.
- Lubricate the pinion seal. Use Motorcraft SAE 80W90 Thermally Stable 4x4 Axle Lubricant meeting Ford specification WSP-M2C197-A.
- Install the pinion seal.
Lubricate the pinion flange splines. Use Motorcraft SAE 80W90 Thermally Stable 4x4 Axle Lubricant meeting Ford specification WSP-M2C197-A.
NOTENever use a metal hammer on the pinion flange or install the flange with power tools. If necessary, use a plastic hammer to tap on a tight fitting flange.
NOTEDo not loosen the nut to reduce preload. Install a new collapsible spacer and nut if preload reduction is necessary.
Align the index marks and install the pinion flange.
- Use the special tool to hold the pinion flange while tightening the nut to set the preload.
- Tighten the nut, rotating the pinion occasionally to ensure the differential pinion bearings are seating correctly. Take frequent differential pinion bearing preload readings by rotating the pinion with a Nm (inch-pound) torque wrench. The final reading must be 0.56 Nm (5 inch lbs.) more than the initial reading taken during removal.
- Align the index marks and position the front driveshaft.
- Install the universal joint spider retainers and bolts.
- Check the fluid level and, if necessary, fill the axle to specification. Use Motorcraft SAE 80W90 Thermally Stable 4x4 Axle Lubricant meeting Ford specification WSP-M2C197-A.
- Lower the vehicle.
- If so equipped, reactivate the air suspension.