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GM additive

Discussion in 'Chevy Trucks' started by dlcs, Aug 13, 2005.

  1. dlcs

    dlcs 2000 Club Member
    Messages: 2,142

    Can someone tell me why GM uses a special additive to limited slip differentials?
  2. Bad Luck

    Bad Luck Senior Member
    Messages: 741

    Good question. I have the G80 and do not add anything to the Mobil 1 I put in it.
  3. calhoun

    calhoun Senior Member
    Messages: 165

    In a limited slip you have power at all times to each wheel. When cornering one need to turn faster than the other so slippage is needed. The additive makes the slippage smoother. These are used in many GM cars.

    If you are talking about trucks however. Chev trucks don't come with limited slip. They come with G80 lockers. You don't use any additive with this rear end. They only lock when needed no slippage is required. If you add an additive to make it slip better you are defeating it's purpose.
  4. lawnmedic

    lawnmedic Senior Member
    Messages: 703

    According to my GM shop manuals( both the 98 and the 01 ) the "Limited Slip" diff.s require an anti foaming additive added to the gear lube...
  5. dlcs

    dlcs 2000 Club Member
    Messages: 2,142

    But it doesn't say the 99 2500 need the additive?

    JRKRACE Senior Member
    Messages: 172

    The new additive they use now is called "grape juice". This is the specified lube as ststed by Eaton. They are using it in all the G 80 locking differentials on the 2500 and 2500 HD as far as I know. They also use it on my wife's 2002 Yukon XL 1/2 ton. This stuff goes for about 26.00 a quart. :eek: I use it because I'm still under warranty but I've heard Mobil 1 is just as good and a lot cheaper. I'm sure you won't have a problem with either.

    The "additive" you are thinking about is the stuff that comes in a little 4 oz bottle that you add to the lube to prevent the "chatter" you hear and feel when making turns. IIRC, this is for "limited slip" applications and not "locking" rear ends. This is the stuff I used to use on my 87 Grand National and it used to work well...I don't think it's meant for your 2500...