What Diff Do I Have ?

Discussion in 'General Tech' started by 97JF, Oct 1, 2019.

  1. 97JF

    97JF Member

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    Please could someone tell me what diff I have on my 1997 Mustang GT ? Pics below

    Recently bought the car and has a noise from the rear end so going to change the oil and gasket as it looks like it's been leaking.

    Does anyone know what gasket I need to order ? Also what friction modifier ? I think i'm clear on the oil as the owner's manual and Haynes manual both say 80w90

    Many thanks for your help

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  2. lwarrior1016

    lwarrior1016 Legend SN95 Supporter

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    According to the tag it’s an 8.8 rear with 3.08 gears.

    Use 75w-140 oil and a bottle of friction modifier from a parts house. Don’t bother with a gasket, just get a tube of good rtv. The gaskets leak more times than not.
     
  3. 97JF

    97JF Member

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    Thanks, but not use 80w90 like the manual says ?

    Also is it a limited slip diff ? Because just wondering with the friction modifier they sell ones for cars with LSD and cars without, thanks
     
  4. lwarrior1016

    lwarrior1016 Legend SN95 Supporter

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    I dont know about that manual, everything I’ve read says 75w-140, it might have been something that changed over the years. I’ve only ever used 75-140.

    Also, all mustang gt’s with the 8.8 has a limited slip diff.
     
  5. 01yellercobra

    01yellercobra Active Member

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    My understanding was the GT's and earlier Cobras used 80w-90. The 75w-140 was specced for the 03/04 Cobras because they came with carbon fiber clutch packs.

    Will anything bad happen if you use different weight oil? Probably not. Oh, I'd get a Lube Locker gasket. We put one on my son's 8.8 and it's been working fine. And its reusable.