gear swap

Discussion in 'Fox 5.0 Mustang Tech' started by C. C. Stang, Dec 14, 2003.

  1. I want to swap my 3.08's for 3.73's. The car is an 86' GT with 120,000 miles on it. I have a shop that will do the basic labor I will provide the parts. What do I need to order to do this right ? He said something about rebuilding something so the rear doesn't whine do to the high milage on the car. What is he talking about ? :shrug:
  2. The basic parts to buy are the ring/pinion of coarse.
    A crush sleeve and side shims, 3 qts gear lube and friction modifier are a must.
    Yes, you can re-build the posi unit, and buy pinion bearings/seal,
    Inner/outer axle bearings/seals.
    Its all in how much money you want to spend now.
    If the rearend is quiet now then it should be quiet after the gear installation.
  3. anyone else done gears ?
  4. Yeah I just put my 3.73s in about 4 months ago. All my bearings checked good so I just reused them. I bought a kit that had pinionshims, side shims, seal and rear gasket from year one was only like $28. I also used solid spacer for my pinion but I do mine myself. It take a little fiddling to get right. I should have rebuilt posi, with many mile would be a good idea, I wish I would have done mine while I had it out.
  5. WHere did you get it ??
  6. try looking at
  7. Thats a good place or I got mine through Year One. I think the web site is and then click on mustang