Axle Seal - Rear

Replace the rear axle shaft seal to stop differential fluid leaks at the wheel hub. Requires removing the rear wheel, brake components, and axle shaft to access and replace the seal.

Warnings

Tools required

Parts

• Rear axle shaft seal (per side) × 1 — Use OEM Ford seal specification
• Axle shaft nut × 1 — Use new OEM nut if staked type
• Differential cover gasket × 1 — Use OEM or RTV sealant per spec
• Cotter pin (if applicable to axle nut) × 1 — Check specific axle configuration

Fluids

• Motorcraft 75W-140 Synthetic Gear Oil — 2 qt

Preparation

1. Park vehicle on level surface and set parking brake
2. Chock front wheels securely
3. Loosen rear wheel lug nuts while vehicle is on ground
4. Raise rear of vehicle and support securely on jack stands at frame contact points
5. Remove rear wheel on affected side
6. Place drain pan under differential to catch any fluid spillage

Procedure

1. 1

   Remove rear brake caliper and rotor
   Remove the two brake caliper mounting bolts and carefully lift caliper off rotor. Support caliper with wire or caliper hanger - do not let it hang by brake hose. Remove brake rotor by pulling straight off the hub. If rotor is stuck, use rubber mallet to tap it loose.
2. 2

   Remove wheel speed sensor
   Disconnect the ABS wheel speed sensor electrical connector. Remove the sensor mounting bolt and carefully extract the sensor from the axle housing or backing plate. Set aside to prevent damage.
3. 3

   Remove axle shaft retaining nut
   If the axle nut is staked, use a punch or chisel to carefully unstake the nut collar from the axle shaft groove. Use a large socket (typically 35mm or 36mm) and breaker bar to remove the axle shaft retaining nut. The nut is torqued to 184 lb-ft, so significant force will be required. Discard the old nut if it is a staked type.
   ⚠Ensure the vehicle is securely supported before applying breaking force to remove the axle nut.
   Torque spec

   Axle Nut250 Nm (184 lb-ft)
4. 4

   Remove axle shaft from housing
   Attach slide hammer with axle puller adapter to the axle shaft flange or use appropriate puller tool for your specific axle configuration. Apply steady pulling force using the slide hammer to extract the axle shaft from the differential housing. The shaft should slide out with the bearing and seal. Position drain pan to catch differential fluid that will drain from the housing opening.
   ⚠Approximately 1-2 quarts of gear oil will drain from the axle tube. Ensure drain pan is properly positioned.
5. 5

   Remove old axle seal
   Using a seal puller, pick, or small pry bar, carefully remove the old seal from the axle housing bore. Work around the seal perimeter to avoid damaging the housing bore surface. Clean the seal bore thoroughly with shop rags and inspect for any damage, scoring, or corrosion. Use wire brush if needed to clean the bore surface.
   ⚠Do not damage the seal bore surface as this will cause the new seal to leak.
6. 6

   Inspect axle shaft and bearing
   Inspect the axle shaft seal surface for wear, grooves, or damage. Check the axle bearing for roughness, pitting, or excessive play. If the bearing or shaft shows wear, the entire axle shaft assembly should be replaced. Clean the axle shaft seal surface thoroughly before installation.
7. 7

   Install new axle seal
   Lightly coat the outer diameter of the new seal with clean gear oil. Position the seal squarely in the housing bore with the seal lip facing inward toward the differential. Using a seal driver or appropriately sized socket that contacts only the outer edge of the seal, drive the seal into the bore until it is fully seated and flush with the housing face. Tap evenly around the perimeter to ensure proper seating.
   ⚠Do not strike the seal face directly as this will damage the seal. Drive only on the outer metal edge.
8. 8

   Prepare axle shaft for installation
   Coat the axle shaft seal surface and splines with clean Motorcraft 75W-140 gear oil. Lightly coat the new seal lip with gear oil as well. Ensure the axle shaft is clean and free of any debris that could damage the new seal.
9. 9

   Install axle shaft
   Carefully align the axle shaft splines with the differential side gear splines. Gently push the axle shaft into the housing, being careful not to damage the new seal lip. The shaft should slide in smoothly and seat fully into the differential. You may need to rotate the shaft slightly to align splines. Push firmly until the shaft is fully seated and the bearing is in position.
   ⚠Do not force the axle shaft. If excessive resistance is felt, remove and check spline alignment to avoid seal damage.
10. 10

    Install and torque axle shaft nut
    Install the new axle shaft retaining nut onto the shaft threads. Torque the nut to 250 Nm (184 lb-ft) using a calibrated torque wrench. If the nut is a staked type, use a punch to stake the nut collar into the axle shaft groove at the designated location. If using a cotter pin type, install a new cotter pin and bend the ends properly.
    ℹ️Always use a new axle nut if it is the staked type. Reusing staked nuts may result in loosening.
    Torque spec

    Axle Nut250 Nm (184 lb-ft)
11. 11

    Reinstall wheel speed sensor
    Clean the wheel speed sensor mounting hole if needed. Insert the ABS wheel speed sensor into its mounting location and secure with the mounting bolt. Reconnect the electrical connector. Ensure the sensor has proper clearance and is not damaged.
12. 12

    Reinstall brake rotor and caliper
    Slide the brake rotor onto the hub and secure with a lug nut temporarily if needed. Position the brake caliper over the rotor and align the mounting holes. Install the caliper mounting bolts and torque to specification per brake system requirements.
13. 13

    Refill differential fluid
    Locate the differential fill plug on the rear differential cover (passenger side, upper position). Remove the fill plug. Using a fluid pump or funnel with hose, add Motorcraft 75W-140 Synthetic Gear Oil until fluid begins to run out of the fill hole. The rear differential capacity is 2.0 quarts, but fill to the bottom of the fill hole opening. Reinstall and tighten the fill plug.
    ℹ️If both axle seals were replaced, you may need additional fluid beyond 2.0 quarts to account for spillage.
14. 14

    Reinstall wheel and lower vehicle
    Install the rear wheel onto the hub. Thread all lug nuts by hand to prevent cross-threading. Torque the lug nuts to 140 Nm (103 lb-ft) in a star pattern using a torque wrench. Lower the vehicle to the ground and perform final torque verification on lug nuts with vehicle weight on wheels.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification
2. Verify brake system operation before driving
3. Check that parking brake functions properly
4. Confirm no fluid leaks around axle seal area after installation

Verification

• Start vehicle and verify no ABS warning lights are illuminated
• Test drive vehicle and verify proper brake operation and no unusual noises from rear axle
• After test drive, inspect the axle seal area for any signs of gear oil leakage
• After 50-100 miles, recheck differential fluid level at fill plug and top off if needed
• Verify axle nut remains properly torqued and secured (staked or cotter pinned)

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