Axle Seal - Front

Replace the front axle shaft seal on a 1972 Ford F-100 with Dana 44 front axle to prevent differential fluid leaks at the wheel end.

Warnings

Tools required

Parts

• Front axle shaft seal × 1 — Use OEM specification for Dana 44 front axle
• Wheel bearing outer locknut × 1 — Replace if damaged during removal
• Axle shaft gasket or O-ring × 1 — Verify axle stub shaft seal type

Fluids

• 80W-90 GL-5 gear oil — 1 qt

Preparation

1. Park vehicle on level ground and engage parking brake
2. Place wheel chocks behind rear wheels
3. Loosen front wheel lug nuts while vehicle is on the ground
4. Raise front of vehicle and support securely on jack stands under the frame rails
5. Remove front wheel and tire assembly
6. Position drain pan under front axle tube on the side being serviced

Procedure

1. 1

   Remove the manual locking hub assembly
   If this is a 4WD truck equipped with manual locking hubs, turn the hub dial to FREE position. Remove the hub cap retaining bolts (count varies by hub manufacturer, typically Allen-head) securing the hub cap assembly to the wheel hub. Carefully pull the hub assembly straight off the spindle, noting the position of any shims or spacers behind it. If equipped with automatic hubs, remove the hub retaining snap ring and pull the complete hub assembly off.
2. 2

   Remove the wheel bearing locknut and washer
   Using a hub socket or large adjustable wrench, remove the outer wheel bearing locknut. This nut is typically a slotted or castellated nut that may have a lock ring behind it. Remove the lock ring or lock washer, then remove the inner adjusting nut. Keep these components organized as they must be reinstalled in the correct order.
3. 3

   Remove the wheel hub and outer bearing
   Carefully pull the wheel hub straight off the spindle. The outer wheel bearing cone will come out with the hub. Set the hub aside on a clean surface. Remove the outer bearing from the hub and inspect it for wear. The brake rotor is typically integral with the hub on these models.
4. 4

   Remove the inner wheel bearing and grease seal
   Using a seal puller or large flathead screwdriver, pry out the inner wheel bearing grease seal from the back of the hub. The inner bearing cone will come out with the seal or can be removed separately. Inspect the bearing and races for pitting or wear.
5. 5

   Remove the spindle and backing plate assembly
   Remove the nuts/bolts securing the spindle and brake backing plate to the axle housing knuckle (typically 6 on Ford Dana 44 spindles — verify count for your axle). The spindle, backing plate, and brake assembly will come off as a unit. Support the brake assembly with a bungee cord or wire to avoid stressing the brake hose. Do not let the assembly hang by the brake line.
6. 6

   Remove the axle shaft
   Pull the axle shaft straight out of the axle housing. The shaft should slide out with moderate force. If resistance is encountered, gently work the axle shaft assembly out of the housing by hand; do not force it. The outer shaft/U-joint assembly slides out of the tube after spindle removal. Only a small amount of residual gear oil may be present near the tube end; position your drain pan to catch any fluid.
7. 7

   Remove the old axle seal
   Using a seal puller or large flathead screwdriver, carefully pry the old axle seal out of the axle tube bore. Work around the seal perimeter to avoid damaging the axle housing bore. Once the seal is loose, pull it completely out. Inspect the seal bore for any scoring, burrs, or damage that could compromise the new seal.
8. 8

   Clean and inspect the axle tube bore
   Use a wire brush and brake parts cleaner to thoroughly clean the seal bore in the axle tube. Remove all old seal residue, rust, and debris. Inspect the bore for scratches or damage. Minor surface rust can be cleaned with fine sandpaper. Check the axle shaft seal surface for grooves or wear that could cause the new seal to leak.
9. 9

   Install the new axle seal
   Lightly coat the outer diameter of the new seal with gear oil. Position the seal squarely in the axle tube bore with the seal lip oriented per factory specification (typically facing the differential/oil side — verify for this axle before installing). Using a seal driver or large 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 axle housing face. Tap evenly around the seal perimeter to ensure straight installation.
10. 10

    Inspect and reinstall the axle shaft
    Inspect the axle shaft seal surface for grooves or wear. Minor surface imperfections can be smoothed with fine emery cloth. Lightly coat the axle shaft seal surface with clean gear oil. Carefully slide the axle shaft into the axle tube, guiding it past the new seal. Push the shaft in until it fully engages with the differential side gears. You should feel the shaft splines engage with a definite stop.
11. 11

    Reinstall the spindle and backing plate assembly
    Position the spindle and backing plate assembly onto the axle housing knuckle, ensuring proper alignment of the bolt holes. Install the 4 spindle bolts and tighten in a crisscross pattern. Tighten the spindle-to-knuckle fasteners in a crisscross pattern to the factory-specified torque (verify against Ford/Dana service data — do not guess).
12. 12

    Reinstall the inner wheel bearing and seal
    Pack the inner wheel bearing with fresh wheel bearing grease. Place the bearing into the inner race in the hub. Install a new inner bearing grease seal by tapping it gently into place with a seal driver or large socket until it is flush with the hub face. Ensure the seal is seated evenly.
13. 13

    Reinstall the wheel hub assembly
    Pack the outer wheel bearing with fresh wheel bearing grease. Slide the wheel hub onto the spindle, being careful not to damage the inner seal. Install the outer wheel bearing cone into the outer race. Install the inner adjusting nut and tighten while rotating the hub to seat the bearings. Adjust bearing preload according to factory specifications, then install the lock washer and outer locknut. Verified detail (This wheel bearing adjustment guess is not verified. Ford/Dana front hub bearing procedures typically specify seating the bearing at a torque (e.g. ~50 ft-lb), then backing off and re-torquing to a much lower final preload spec; the '1/4 turn back off' figure is invented and could leave the bearing too loose or too tight.): Follow the factory Ford/Dana 44 front wheel bearing adjustment procedure exactly (seat bearings at specified torque while rotating hub, then back off and set final preload to spec) — do not use an estimated value.
14. 14

    Reinstall the locking hub assembly
    Install any shims or spacers that were removed. Position the locking hub assembly onto the wheel hub, ensuring proper alignment of the bolt holes. Install the hub cap retaining bolts and tighten in a star pattern to the hub manufacturer's specified torque (these are small fasteners — verify the spec, as it is typically much lower than 30 ft-lbs). If equipped with automatic hubs, install the hub assembly and secure with the retaining snap ring.
15. 15

    Refill the front differential
    Locate the front differential fill plug on the front axle housing. Locate the differential fill plug on the front axle housing. Remove the fill plug and add 80W-90 GL-5 gear oil only as needed until it reaches the bottom of the fill hole; pulling one axle shaft typically does not drain the differential, so little or no fluid may be required. Reinstall the fill plug and tighten securely. Reinstall the fill plug and tighten securely.

Reassembly

1. Reinstall the wheel and tire assembly
2. Hand-tighten all lug nuts in a star pattern
3. Lower the vehicle to the ground
4. Torque the lug nuts to factory specification (approximately 75-85 ft-lbs) in a star pattern
5. Test the locking hub operation by engaging and disengaging the hub dial if equipped with manual hubs

Verification

• Check for gear oil leaks around the axle seal after the vehicle has been driven for 10-20 miles
• Verify that the wheel bearing has no excessive play by grasping the tire at 12 and 6 o'clock positions and checking for movement
• Ensure the locking hub engages and disengages properly in 4WD mode
• Verify the front differential is filled to the proper level by checking the fill plug level after the vehicle has sat for several hours
• Test drive the vehicle and listen for any unusual noises from the front axle area

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