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How to Install a Differential cover on your 1986-2013 Mustang GT, Mach 1, Cobra, GT500 and V6

Installation Time

1 hours

Tools Required
  • 3/8" Drive Ratchet
  • ½" 3/8" Drive Socket (stock cover bolts)
  • Small Pry Bar or Flat Blade Screwdriver
  • Scraper
  • 3/8" Drive Torque Wrench
  • 7/32" Hex Socket (girdle bolts)
  • 6mm Hex Socket (load bolts)
  • 22mm Wrench (jam nuts)
  • 10mm Hex Socket (girdle fill plug)
  • ½“ Drive Ratchet
  • 18mm ½" Drive Socket (panhard bar)
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1. Safely raise and support vehicle to gain access.    

2. If removal of a panhard bar is necessary. Loosen bolt on drivers side of panhard bar and remove bolt on the passenger side with 18 mm socket and ratchet. Panhard bar can now swing out of the way for better access. Reinstall in reverse order, tightening bolts when vehicle is on the ground.    

3. Place drain pan under the differential.    

4. Loosen all 10 of the stock cover bolts.    

5. Loosen the top bolt half way and remove 9 other bolts.    

6. Using a small pry bar or flat blade screwdriver, gently pry the stock cover loose allowing fluid to drain.    

7. Remove top bolt and remove stock cover.    

8. Inspect all internal parts for excessive wear or damage.    

9. Using scraper, remove all gasket material from the mating surface making sure no material is left inside the housing.   

10. Make sure the load bolts are backed out completely so they do not make contact with bearing caps.    

11. Apply a bead of silicone sealant to the girdle cover following the silicone manufacturer’s instructions.    

12. Install the girdle cover by first starting the top bolt and then adjust the cover as needed to start all other bolts.    

13. Torque all bolts to 25 ft. lbs. in the sequence shown.    

14. Snug load bolts by hand until they contact bearing caps.    

15. Torque load bolts to 5 ft. lbs.    

16. Holding load bolts in place, tighten jam nuts enough to keep load bolts from moving.    

17. Remove fill plugs from girdle cover and differential housing.    

18. Fill differential with specified gear oil until fluid flows from factory fill hole.    

19. Reinstall fill plugs and check for leaks.    

20.  You have completed the installation of your rear girdle!    

Installation Instructions written by AmericanMuscle customer Trafton Cain 7/18/12  ​