Monkey Grip Limited Slip?

Discussion in 'Got gears?' started by jmos4, Apr 25, 2023.

  1. jmos4

    jmos4 Well-Known Member

  2. knucklebusted

    knucklebusted Well-Known Member

    I'd ask Brian Trick or MonzaZ about. They should have the skinny on them if they are good or junk.
  3. TrunkMonkey

    TrunkMonkey Well-Known Member

    Cheap Chinese crap. At your peril.
  4. BrianTrick

    BrianTrick Brian Trick

    They end up back on eBay broken. You get what you pay for. The majority of my posi unit installs now are the Tru Trac helical gear units. They can take a good amount of punishment and don’t have cones or clutches to wear out. No additive needed either.
    Waterboy likes this.
  5. jmos4

    jmos4 Well-Known Member


    Looking for a 8.2 BOP posi and would like something besides a Eaton or Auburn style as don't believe they make a True Track for it.

  6. john.schaefer77

    john.schaefer77 Well-Known Member

    Talk to Brian above. He adapts the eaton trutrac fit the 8.2. That's what I run, he built it, must be 4 years now. It is a great differential.
  7. Houndogforever

    Houndogforever Silver Level contributor

    On a positive note, at least somebody is trying to make a replacement, even if it is chinesium iron.
  8. BrianTrick

    BrianTrick Brian Trick

    I modify and machine the Tru Trac to fit the 68-70 Buick 8.2”.
    As far as the common BOP 8.2”,your choices are an Auburn,and Eaton clutch unit,or a Yukon,which is a copy of an Eaton. Some of us have been pushing for Eaton to make a Tru Trac for the 8.2” BOP,but nothing yet.
    FLGS400 likes this.
  9. jmos4

    jmos4 Well-Known Member


    Would be nice if they do, if you machined one to fit the 68-70 version, could you modify one to fit a standard 8.2 BOP?

    Either way add my name to the list of wanting another alternative for the 8.2.

  10. BrianTrick

    BrianTrick Brian Trick

    Think of the posi unit as a cylinder. The 8.5” unit is too large in diameter to fit the 8.2” ring gear onto. It’s not just the journal where the ring gear presses onto. The whole thing. I haven’t spec’d out any other Tru Trac units to see if they could be modified. The 68-70 Buick has a larger inside diameter for the ring gear.
    Let’s go back to the “cylinder” for a minute. You can only make these units so strong because you can only fit so much inside of that cylinder,whether it’s a Tru Trac,clutch unit,or cone unit. The smaller the cylinder(8.2”,7.5”) the smaller the parts and the lesser the load or abuse they will handle.
  11. jmos4

    jmos4 Well-Known Member

    Hi again,

    Makes sense what you're saying, it would be nice to get a posi that didn't wear like the Eaton or Auburn.

  12. BrianTrick

    BrianTrick Brian Trick

    I think that’s what it comes down to. To design and build a helical unit for an 8.2” or 7.5” would leave the worm gears very small and not able to handle enough load. That is my gues. The next time I have a BOP 8.2” ring gear,I will play around with it. Possibly open up the ID to make it able to fit an 8.5” carrier. Maybe.
  13. Super Bald Menace

    Super Bald Menace Frame off oil changes

    Honestly as little as these classic cars are driven these days an Eaton or Yukon carrier should last a very long time before rebuild is needed. The Auburn is the one I'd steer clear of.
  14. jmos4

    jmos4 Well-Known Member


    Just a thought as was looking around and noticed that they make a True Track for a 8.0 Toyota, I would imagine the ring gear I'd would be close?

    4cyl: 913A611
    V6: 913A610

    Both 30 spline

    Then the big task would be 30 spline axle shafts...might help with strength?

    Either way if you come up with something let us know, as I have one to build this year , with a 3.90 for my Oldsmobile, and would rather not buy twice. And new axle shafts are on my list as well.

    Currently have a newer Auburn in my 65 Buick now.

  15. monzaz

    monzaz Jim

    8.2chevy, 8.2pontiac, 8.2 68-70 all the same inner diameter ring.
    It is the ring gear offset that are the problems in the carriers. ONLY certain ratios can be fit on the 8.5 conversion and stay centered.
    GM makes a torsen posi so and true trac make s a true tac for 7.5 and 7.6. already.
    8.2 Chevy and 8.2 BOP are left out... Just not enough people like they are worth building...So that is what the companies look for HOW MUCH do you think will sell. UNTIL they get numbers worthy of mass production in these you will not see it.
    JD Race
  16. BrianTrick

    BrianTrick Brian Trick

    I wasn’t aware they made one for the 7.5”,but then again,I think I’ve only built one of those in my whole life. I was think the the ID of the 8.2” BOP ring gear was smaller. Maybe I’m thinking of something else. I can figure out the position of the ring gear flange as I’ve had to do that for the 68-70 Buick units. Yes,you could upgrade to a 30-spline axle with an 8.2”.

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