Axle Shaft - Rear

Remove and replace the rear axle shaft on a 1972 Ford F-100 with semi-floating axle assembly, including bearing and seal service.

Warnings

Tools required

Parts

• Rear axle shaft × 1 — Use OEM specification
• Axle shaft bearing × 1 — Use OEM specification
• Axle shaft seal × 1 — Use OEM specification
• Brake backing plate gasket × 1 — Use OEM specification or RTV sealant
• Differential cover gasket × 1 — Use OEM specification

Fluids

• 80W-90 GL-5 gear oil — 3.5 qt

Preparation

1. Park vehicle on level ground and place wheel chocks in front of front wheels.
2. Loosen lug nuts on the wheel for the side being serviced while vehicle is still on the ground.
3. Raise rear of vehicle with floor jack at rear axle housing.
4. Place jack stands under frame rails behind rear axle, ensuring vehicle is stable.
5. Remove wheel and tire assembly completely.
6. Place drain pan under differential housing to catch gear oil.

Procedure

1. 1

   Remove brake drum
   Remove the brake drum from the axle flange. The drum is retained by the wheel lugs only. If drum is stuck due to rust or brake shoe contact, back off the brake adjustment through the backing plate access hole using a brake spoon. Tap drum lightly with rubber mallet if needed. Use brake drum puller if drum is severely stuck.
2. 2

   Remove axle shaft retaining nuts
   Remove the 4 nuts securing the axle shaft retainer plate to the brake backing plate studs. Verify nut size before starting (commonly 9/16 inch or 1/2 inch depending on axle type). Note the orientation of the retainer plate for reassembly.
3. 3

   Extract axle shaft
   Using a slide hammer with axle puller adapter attached to the axle flange bolt holes, extract the axle shaft from the axle housing. Apply steady pulling force. The shaft will pull out approximately 12-14 inches bringing the bearing with it. Gear oil will drain from the housing as the shaft is removed. Have drain pan positioned to catch fluid.
4. 4

   Remove axle shaft seal
   Using a seal puller or pry bar, carefully remove the old axle shaft seal from the axle housing bore. Work around the seal circumference to avoid gouging the housing bore. Clean the seal bore thoroughly with a shop rag.
5. 5

   Inspect and remove bearing from old shaft
   Inspect the bearing on the removed axle shaft. If replacing the shaft, the bearing and retainer will transfer to the new shaft, but this typically requires a press. If reusing the shaft, inspect for scoring, wear, or damage. The bearing is press-fit behind a bearing retainer ring on the shaft. Professional pressing equipment or a hydraulic press is required for bearing removal and installation.
6. 6

   Remove bearing retainer ring
   The bearing retainer ring is pressed onto the axle shaft ahead of the bearing and cannot simply be pressed off. Drill a hole partway through the retainer ring to relieve the press-fit, then split it with a chisel and remove it, taking care not to nick the shaft. This step requires care to avoid shaft damage.
7. 7

   Install bearing retainer on new shaft
   Note: on this axle the bearing is installed first (Step 8), then the retainer ring is pressed on behind the bearing to lock it in place. Verify the correct pressing sequence and retainer orientation against the service manual before assembly.
8. 8

   Install bearing on new shaft
   Press the new axle bearing onto the shaft until it seats against the bearing retainer ring. The bearing cage orientation matters: the bearing should be pressed with the seal side facing the axle flange end. Use a bearing installer tool or hydraulic press with proper support to avoid cocking the bearing.
9. 9

   Install new axle seal
   Install the new axle shaft seal into the axle housing bore. Apply a thin coat of gear oil to the seal lip. Using a seal driver or large socket that matches the seal outer diameter, drive the seal squarely into the housing until it is flush with the housing face or slightly recessed. Do not cock the seal during installation.
10. 10

    Install axle shaft assembly
    Carefully insert the axle shaft into the housing, guiding it through the seal. Rotate the shaft slowly to align the splines with the differential side gear. Push the shaft inward until the bearing seats fully in the housing bore and the shaft is fully inserted. You should feel positive engagement when the splines mesh.
11. 11

    Install backing plate gasket
    Ensure the backing plate mating surface and axle housing face are clean and free of debris or old material.
12. 12

    Install retainer plate and secure axle
    Position the axle shaft retainer plate over the backing plate studs in the correct orientation. Install the 4 nuts and tighten in a crisscross pattern to secure the axle shaft. Torque the retainer plate nuts to the factory specification (approximately 20-40 ft-lbs depending on axle type — verify against the 1972 F-100 service manual) in a crisscross pattern to secure the axle shaft.
13. 13

    Reinstall brake drum
    Install the brake drum onto the axle flange. Ensure the drum seats properly on the flange and rotates freely without binding on brake shoes.
14. 14

    Refill differential
    Refill the rear differential with 80W-90 GL-5 gear oil to the proper level. Remove the fill plug on the axle housing and add fluid until it reaches the bottom of the fill hole (fluid should just begin to seep out). Verify the correct capacity for your axle (Ford 9-inch is approximately 4-5 pints); replace what was lost during axle removal. Reinstall fill plug.

Reassembly

1. Reinstall wheel and tire assembly, tightening lug nuts in a star pattern.
2. Lower vehicle from jack stands and remove stands.
3. With vehicle on ground, torque lug nuts to final specification in star pattern.
4. Test drive vehicle and verify no abnormal noises, vibrations, or fluid leaks from the axle seal.
5. Recheck differential fluid level after test drive and top off if necessary.

Verification

• Verify axle shaft does not have excessive end play by attempting to pull outward on brake drum; shaft should be firmly seated.
• Rotate brake drum to confirm smooth rotation without binding or grinding noises.
• Check for gear oil leakage around the axle seal after test drive.
• Verify no unusual noises from rear axle during test drive, especially during turns.
• Confirm brake operation is normal with no pedal pulsation or pulling.

More procedures for this vehicle