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Limited slip additive

Transmission and Drivetrain

  1. Ralph

    Ralph Well-Known Member

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    Do I need limited slip additive for my 1971 dodge challenger.

    8 3/4" rear end having new ring and pinion installed.

    If so which one do I buy and where do I get it.

    Thanks to all.
     
  2. Mopars & Missiles

    Mopars & Missiles Well-Known Member

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    If you've got a "sure grip" in that axle, then Yes you do need it.

    Go to your local Dodge dealer and get a bottle of the "real thing". They've got it.
     
    • Agree Agree x 1
  3. moparlee

    moparlee Well-Known Member

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    • Agree Agree x 1
  4. Ralph

    Ralph Well-Known Member

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    Thanks to all
     
  5. Mopars & Missiles

    Mopars & Missiles Well-Known Member

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    Here's the Mopar type. P/N 04318060AB

    PB070002.JPG
     
  6. tonysrt

    tonysrt Well-Known Member

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    Is there any difference between the Ford and Mopar additive. We know Ford & Mopar don't make it, so it must be made by some oil Co.. Any other recommendations?
     
  7. Cudafor36

    Cudafor36 Well-Known Member

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    Drive line works recommends KW which you can buy at advance auto. That's what is in mine now.
     
  8. aussiemark

    aussiemark Well-Known Member

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    You can get dedicated limited slip diff oil usually called LS90 and it would probably depend on the type of locking unit used. Is it an after market or OEM unit? the modern Torsen style units use normal GL5 rated gear oil with no additive and the mechanical Detroit locker types prefer a mineral based gear oil with no additive apparently Eaton won't honour a warranty claim if synthetic oil is used, I prefer a proper oil over an additive use the additive in a crappy SUV not a muscle car.
     
  9. mmissile

    mmissile Well-Known Member

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    I've always used non-synthetic with the Ford modifier. Local shop that's been in business for 50 years ["Ring and Pinion"], always use the stuff for mopar/Ford rears. They're the best specialized shop in SE Mi.
     
  10. i_taz

    i_taz Well-Known Member

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    Never assume synthetic is better than dino oil. I put Mobil 1 in my '97 Dodge Ran Van and the pinion bearing of all things went out after <10,000 miles. I would follow mmissle's method. I even
    put a shot of the Ford modifier in my tranny after the lingering effects of Wally World's synthetic transmission fluid caused a shutter in my '02 Ford pickup which should handle a synth fluid but not that one...!
     
  11. booyaballer

    booyaballer Well-Known Member

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    can you add too much additive?

    my 8.75 was rebuilt in april 2017 which has been leaking. i don't recall if i ever added the additive for the posi. if i add a bottle for good measure will that be bad or cause harm?

    thanks.