Axle Seal - Rear

This procedure covers replacement of the rear axle shaft seal on a 2011-2014 Ford F-150 3.5L EcoBoost 4WD, requiring removal of the rear wheel, brake components, and axle shaft to access and replace the seal.

Warnings

Tools required

Parts

• Rear axle shaft seal × 1 — Use OEM specification
• Differential cover gasket × 1 — Use OEM specification
• New cotter pin or axle nut × 1 — Check if nut requires staking or cotter pin
• RTV silicone sealant (if not using gasket) × 1 — Motorcraft TA-357 or equivalent

Fluids

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

Preparation

1. Park vehicle on level ground and engage 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 rails
5. Remove rear wheel on side requiring seal replacement
6. Place drain pan under differential cover

Procedure

1. 1

   Drain differential fluid
   Remove all differential cover bolts and carefully break the seal with a pry bar. Allow gear oil to drain completely into drain pan. Remove cover and gasket material. Clean mating surfaces on both cover and differential housing with wire brush and solvent.
   Torque spec

   Differential Cover Bolts35 Nm (26 lb-ft)
2. 2

   Remove brake caliper and rotor
   Remove brake caliper mounting bolts and hang caliper securely with wire or caliper hanger to avoid stressing brake hose. Do not let caliper hang by brake line. Remove brake rotor from hub. If rotor is stuck, use penetrating oil and light hammer taps to break it free.
3. 3

   Remove axle nut
   Remove cotter pin if equipped, or unstake axle nut. Use breaker bar to loosen axle nut while having helper apply brakes or wedge rotor studs. Remove and discard axle nut (new nut required for reassembly).
   ⚠Axle nut is torqued to 250 Nm and requires significant force to remove. Ensure proper socket engagement to avoid rounding nut.
   Torque spec

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

   Disconnect axle shaft from differential
   From inside differential housing, locate CV joint bolts connecting axle shaft to differential side gear. Remove all CV bolts. Keep bolts organized as they will be reused.
   Torque spec

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

   Remove axle shaft assembly
   Pull axle shaft outward from hub assembly. Once freed from hub splines, rotate and maneuver shaft to remove CV joint from differential housing. Carefully extract entire axle shaft assembly. Inspect CV joint and shaft for damage or excessive wear.
   ⚠Axle shaft is heavy and may have sharp edges. Support weight during removal to prevent injury or damage to brake components.
6. 6

   Remove old axle seal
   Using slide hammer with seal puller attachment, hook inner lip of axle seal and extract from axle tube. Alternatively, carefully pry seal out using seal puller or punch, being extremely careful not to damage axle tube bore surface. Clean seal bore thoroughly with solvent and inspect for damage, burrs, or corrosion.
   ⚠Do not damage axle tube bore or seal seating surface. Any scratches or gouges in this area will cause new seal to leak.
7. 7

   Install new axle seal
   Lightly coat outer diameter of new seal with gear oil. Position seal squarely in axle tube bore opening with seal lip facing inward toward differential. Using appropriately sized seal driver, carefully tap seal into bore until it seats flush with tube end. Ensure seal is installed straight and fully seated around entire circumference.
   ⚠Seal must be driven in straight and evenly. Cocked or partially seated seals will leak immediately upon refilling differential.
8. 8

   Reinstall axle shaft
   Coat axle seal lip with clean gear oil. Carefully insert CV joint end into differential housing, aligning with side gear splines. Push axle shaft inward while rotating slightly to engage splines. Once CV joint is fully seated, align outer end with hub splines and push through hub assembly.
9. 9

   Reconnect CV joint to differential
   Rotate axle shaft to align CV joint bolt holes with differential side gear holes. Install all CV bolts and torque to specification in a cross pattern.
   Torque spec

   CV Bolts70 Nm (52 lb-ft)
10. 10

    Install new axle nut
    Install new axle nut on axle shaft. Torque axle nut to specification while preventing hub rotation. After torquing, install new cotter pin or stake nut as required by design.
    ℹ️Never reuse old axle nut. Always use new nut and secure with cotter pin or by staking as specified.
    Torque spec

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

    Reinstall differential cover
    Install new gasket on differential cover or apply RTV silicone bead to cover mating surface per manufacturer specifications. Position cover on differential housing and install all bolts hand-tight. Torque cover bolts to specification in a cross pattern working from center outward.
    Torque spec

    Differential Cover Bolts35 Nm (26 lb-ft)
12. 12

    Refill differential with gear oil
    Locate differential fill plug on front of differential housing. Remove fill plug. Using gear oil pump, add Motorcraft 75W-140 Synthetic Gear Oil until oil begins to seep from fill hole (approximately 2 quarts). Reinstall fill plug.
    ℹ️Differential must be filled to proper level. Oil level should be at bottom of fill plug hole when vehicle is level.
13. 13

    Reinstall brake components and wheel
    Reinstall brake rotor on hub. Reinstall brake caliper and torque mounting bolts to specification. Install wheel and hand-tighten lug nuts in star pattern. Lower vehicle to ground and torque lug nuts to specification in star pattern.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification before test driving
2. Allow RTV sealant to cure per manufacturer instructions before driving if used instead of gasket
3. Double-check that axle nut is properly secured with cotter pin or staking

Verification

• Test drive vehicle and verify no abnormal noises from rear axle
• After test drive, inspect differential cover and axle seal area for any signs of gear oil leakage
• Check differential fluid level at fill plug after 50-100 miles and top off if necessary
• Verify proper brake operation and no brake pedal pulsation

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