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Differential Gear Swap Pattern Check

Discussion in 'GM Powertrain' started by ippielb, Nov 5, 2011.

  1. ippielb

    ippielb New Member

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    Just curious to see if anyone knows if this is an acceptable pattern.


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    Let me know.
    #1
  2. 2COR517

    2COR517 New Member

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    Looks like the pinion isn't quite deep enough. What's your backlash spec? .015" sounds like a lot.
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  3. ippielb

    ippielb New Member

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    This is my base set up. I'm going from here, i will try to reduce the shim on the main bearing. Once i get pinion depth i'll go after backlash, i do not know what the spec is suppose to be on the gears, i cannot find it anywhere in the book they supplied. My gears are USA Gear, in a green box.
    #3
  4. LURCH

    LURCH New Member

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    I was thinking .007/.009 and I agree on the pinion depth.
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  5. 2COR517

    2COR517 New Member

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    You need MORE shim under the inner pinion bearing. That will push it towards the center of the ring gear.
    #5
  6. ippielb

    ippielb New Member

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    Here's what i got now, 0.007 backlash.

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    And the pattern seems more rounded and centered. I can say I'm happy with this pattern. Does seem like the pinions too far out on the drive side though.... Coast side is perfect.

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    #6
  7. ippielb

    ippielb New Member

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    I got ambitious and changed the pinion depth...


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    Let me know what you think, tomorrow i'm sealing it all up.
    #7
  8. TRPLXL2

    TRPLXL2 New Member

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    Very interesting post here, I learned something new today! My dad is very old school as he used to take a piece of newspaper and roll it through the gears, he would make his adjustments based on how the paper came out....
    #8
  9. 2COR517

    2COR517 New Member

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    Looks good to me. Just curious, did you use a setup bearing for the inner pinion?
    #9
  10. ippielb

    ippielb New Member

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    I re-did it again and got basically the same pattern with 0.005"-0.006" backlash, so i'm going to stick with that.

    I took a brand new bearing and bored out the inside so that it could slip on and off. The bearings from my rebuild kit from stock differ in size and angle. So i couldnt use the stock bearing for set up. Had to buy a whole new bearing. Well worth the $30.
    #10

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