This procedure replaces the rear differential cover gasket to repair leaks, requiring the removal of the differential cover, cleaning of mating surfaces, installation of a new gasket, and refilling with fresh gear oil.

Warnings

Tools required

Parts

• Rear differential cover gasket × 1 — Use OEM specification or Motorcraft equivalent
• Rear differential cover bolts (if corroded) × 10 — Use OEM specification

Fluids

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

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks in front of both front wheels
3. If recently driven, allow differential to cool for 30+ minutes
4. Raise rear of vehicle with floor jack and support securely on jack stands rated for vehicle weight
5. Verify vehicle is stable before working underneath
6. Position drain pan under rear differential cover

Procedure

1. 1

   Remove differential cover bolts
   Using a 3/8" socket, loosen all differential cover bolts in a crisscross pattern, working from the outside toward the center. Remove all bolts except the top two, leaving them partially threaded to keep cover from falling.
2. 2

   Drain differential fluid
   Carefully pry the bottom of the differential cover away from the housing using a plastic scraper to break the gasket seal. Allow gear oil to drain completely into drain pan. Once draining slows, remove the final two bolts and carefully remove the cover. Tilt cover to drain any remaining oil into pan.
   ⚠Gear oil will pour out quickly once seal is broken. Ensure drain pan is properly positioned.
3. 3

   Clean differential cover
   Remove all old gasket material from the differential cover using a plastic scraper. Avoid gouging the aluminum surface. Clean the cover thoroughly with brake cleaner and wipe dry with a lint-free rag. Inspect cover for cracks or damage.
4. 4

   Clean differential housing mating surface
   Carefully remove all old gasket material from the differential housing mating surface using a plastic scraper. Use extra care not to allow debris to fall into the differential. Wipe the surface clean with a rag dampened with brake cleaner. Ensure the surface is completely clean and dry.
   ⚠Keep debris and old gasket material from falling into the differential housing. Cover opening with a clean rag if needed.
5. 5

   Inspect differential internals
   With cover removed, visually inspect ring gear, pinion gear, and bearing surfaces for unusual wear, metal shavings, or damage. Check the magnetic drain plug (if equipped) for excessive metal debris. This is normal wear, but large chunks indicate potential problems.
6. 6

   Install new gasket and cover
   Position new gasket on the differential cover, aligning all bolt holes. Carefully lift cover with gasket into position on the differential housing, ensuring gasket stays aligned. Start all cover bolts by hand, threading them in several turns to hold the cover in place.
   ℹ️Some gaskets are designed to be installed dry, others may require a thin bead of RTV sealant. Follow gasket manufacturer instructions.
7. 7

   Torque differential cover bolts
   Using a torque wrench, tighten all differential cover bolts in a crisscross pattern to specification. Start from the center and work outward, making multiple passes with gradually increasing torque until final specification is reached. This ensures even gasket compression.
   Torque spec

   Differential Cover Bolts35 Nm (26 lb-ft)
8. 8

   Refill differential with gear oil
   Locate the differential fill plug on the front or side of the differential housing. Remove fill plug. Using a fluid pump or squeeze bottle, add Motorcraft 75W-140 Synthetic Gear Oil through the fill hole until oil reaches the bottom of the fill plug hole (oil should just start to seep out). Install and tighten fill plug to specification.
   ℹ️Fill capacity is approximately 2.0 quarts, but fill to plug level rather than by volume. Actual capacity may vary slightly.
9. 9

   Lower vehicle and clean up
   Wipe down differential housing to remove any spilled gear oil. Lower vehicle from jack stands. Dispose of used gear oil properly at a recycling center or auto parts store.

Reassembly

1. Ensure all differential cover bolts are torqued to specification in a crisscross pattern
2. Verify fill plug is installed and tightened
3. Check for any gear oil leaks around the new gasket before moving vehicle

Verification

• Start engine and allow to idle briefly, then shut off
• Inspect differential cover gasket area for any signs of leakage
• Drive vehicle for 10-15 minutes, then recheck for leaks with vehicle on level ground
• After 50-100 miles of driving, perform final leak inspection to confirm repair success

More procedures for this vehicle