Axle Shaft - Rear

This procedure covers the removal and replacement of the rear axle shaft on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine and independent rear suspension with CV-style axle shafts.

Warnings

Tools required

Parts

• Rear axle shaft assembly × 1 — Use OEM specification for IRS models
• Axle seal × 1 — Inner differential seal
• Axle nut × 1 — New nut required if staked type
• Cotter pin or staking hardware × 1 — Per torque spec requirements
• Differential cover gasket × 1 — If differential must be opened

Fluids

• Motorcraft 75W-140 Synthetic Gear Oil — 2.5 qt

Preparation

1. Verify vehicle has independent rear suspension (IRS) by inspecting rear suspension configuration
2. Park vehicle on level surface and set parking brake
3. Place wheel chocks in front of front wheels
4. Loosen wheel lug nuts on affected side while vehicle is on ground
5. Raise rear of vehicle and support securely on jack stands at manufacturer-specified jacking points
6. Remove rear wheel on affected side
7. Clean area around axle nut and differential to prevent contamination

Procedure

1. 1

   Remove axle nut
   If axle nut is staked, use a chisel or punch to unstake the crimped portion. Have an assistant apply brakes or use a brake pedal depressor to prevent hub rotation. Use a breaker bar or impact wrench to remove the axle nut. This nut requires significant torque and should not be reused if it is a staked type.
2. 2

   Disconnect brake caliper
   Remove the two caliper mounting bolts and secure the caliper to the suspension or frame using wire or a bungee cord. Do not allow the caliper to hang by the brake hose. Remove the brake rotor if it interferes with axle shaft removal.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
3. 3

   Disconnect wheel speed sensor
   Locate the ABS wheel speed sensor connector near the knuckle. Disconnect the electrical connector and remove any retaining clips securing the sensor wire to the knuckle or suspension components. Remove the wheel speed sensor mounting bolt if necessary to provide clearance.
4. 4

   Disconnect inner CV joint from differential
   Position drain pan under differential to catch gear oil. Locate the six CV joint bolts connecting the inner axle shaft flange to the differential output flange. Remove all six bolts. Support the axle shaft to prevent it from falling. Gear oil will begin to drain once the connection is broken.
   ⚠Approximately 1-2 quarts of gear oil will drain when CV joint is disconnected. Ensure drain pan is properly positioned.
   Torque spec

   CV Bolts70 Nm (52 lb-ft)
5. 5

   Remove outer axle shaft from hub
   With the axle nut removed, the outer splined end must be pressed or pulled from the wheel hub. Use a hub puller or brass drift to push the axle shaft out of the hub bearing. If the shaft is stuck, apply penetrating oil and allow to soak. A slide hammer with axle puller attachment can be used on the inner CV joint end to pull the entire assembly rearward.
   ⚠Do not strike the CV joint or axle shaft threads with a steel hammer as this will damage components.
6. 6

   Remove axle shaft assembly
   Once the outer splines are clear of the hub, carefully maneuver the complete axle shaft assembly away from the vehicle. The shaft may need to be angled to clear suspension components. Support the shaft weight to prevent damage to the CV joints.
7. 7

   Inspect and replace differential seal
   With the axle removed, inspect the inner differential seal for damage or leaking. Use a seal puller or pry bar to carefully remove the old seal from the differential housing. Clean the seal bore with a wire brush and wipe clean. Install the new seal using a seal driver or appropriate socket, ensuring it seats fully and squarely in the bore.
   ℹ️The differential seal should be replaced whenever the axle shaft is removed to prevent future leaks.
8. 8

   Prepare new axle shaft
   Inspect the new axle shaft for any shipping damage. Clean the splines on both inner and outer ends. Apply a thin coat of gear oil to the inner seal contact area and splines. Check that the inner CV joint flange bolt holes are clean and free of debris.
9. 9

   Install axle shaft into hub
   Carefully insert the outer splined end of the axle shaft through the hub bearing. Align the splines and push the shaft through until it is fully seated in the hub. The shaft should slide in with moderate resistance. Do not force or hammer the shaft into place.
10. 10

    Connect inner CV joint to differential
    Align the inner CV joint flange with the differential output flange. Rotate the axle shaft as needed to align the bolt holes. Insert all six CV joint bolts and thread them by hand to ensure proper alignment. Torque bolts in a criss-cross pattern to specification.
    Torque spec

    CV Bolts70 Nm (52 lb-ft)
11. 11

    Install and torque axle nut
    Install the new axle nut onto the outer axle shaft threads. Have an assistant apply brakes or use a brake pedal depressor. Torque the axle nut to specification. If using a staked nut, stake the nut into the shaft groove using a chisel. If using a castellated nut, install a new cotter pin and bend the ends to secure.
    ℹ️The axle nut must be torqued to 250 Nm (184 lb-ft). Use of a torque wrench is critical for proper hub bearing preload and safety.
    Torque spec

    Axle Nut250 Nm (184 lb-ft)
12. 12

    Refill differential
    Using a fluid pump, add Motorcraft 75W-140 Synthetic Gear Oil through the differential fill plug until fluid begins to drip from the fill hole. The differential should be level during filling. Install the fill plug and torque to specification if applicable. Total capacity is approximately 2 quarts, but add fluid until it reaches the fill hole level.
13. 13

    Reinstall brake components and wheel speed sensor
    Reinstall the brake rotor if removed. Position the brake caliper over the rotor and install the mounting bolts. Torque to specification. Reconnect the wheel speed sensor electrical connector and secure any wire clips.
    Torque spec

    Mounting Bolts31 Nm (23 lb-ft)
14. 14

    Install wheel and perform final checks
    Install the wheel and hand-tighten lug nuts in a star pattern. Lower the vehicle until the tire just contacts the ground. Torque wheel lug nuts to specification in a star pattern. Fully lower the vehicle and remove jack stands.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all fasteners have been torqued to specification, particularly the axle nut at 250 Nm (184 lb-ft)
2. Verify the axle nut is properly staked or has a new cotter pin installed
3. Check differential fluid level is correct and fill plug is installed
4. Verify brake caliper is properly secured and brake hose is not twisted or kinked
5. Confirm wheel speed sensor is connected and wire is properly routed away from moving components

Verification

• Start the engine and verify no unusual noises from the rear differential
• Check for gear oil leaks around the axle seal and differential cover
• Test drive the vehicle at low speed in a safe area, listening for clicking, popping, or grinding noises from the CV joint
• Verify ABS warning light is not illuminated on the instrument cluster
• Perform figure-eight turns in both directions to load the CV joint and verify smooth operation
• After test drive, recheck differential fluid level and inspect for leaks
• Verify wheel lug nuts remain properly torqued after 50-100 miles of driving

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