8.5 10 bolt high pitch whine

Discussion in 'Transmission & Driveline Topics' started by haroldpo6, Sep 2, 2019.

  1. haroldpo6

    haroldpo6 Veteran Member

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    Had my 8.5 rebuilt with new gear & pinion w/bearings, seals, axle bearings,etc from a guy that has rebuilt them a lot. It has a high pitch whine between 2000rpm and 2500rpm then quits. He said he took it back apart 3 times and can find nothing wrong.
    Whats wrong with it?
    Its a 1976 rear axle I installed in a 1970
     
  2. camaro71/holland

    camaro71/holland Veteran Member

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    If he's 100% positive about the setup it could be the way it's cut. Then you just can't get it right. Richmond gears BTW?

    Or it wasn't right the first time and you drove too long with it. Then you won't loose it, no matter how good the latter setup will be.
     
  3. badazz81z28

    badazz81z28 Veteran Member

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    My last 8.5 was using Richmond gears with no issues. Are you positive it’s the rear? Rule out the rest of the driveline?
     
  4. haroldpo6

    haroldpo6 Veteran Member

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    Used motive gear and master bearing kit from them also. He said he has it right, can't understand the whine. Only drove a few miles so far.
     
  5. big gear head

    big gear head Veteran Member

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    Most of the time a gear noise has nothing to do with RPMs. Gear noise is usually related to MPH. If it's a 2 cut gear and he set it up like a 5 cut gear then the backlash may be too loose. Sometimes a gear just makes noise no matter how wel it's set up, especially if it was a cheap gear.
     
  6. haroldpo6

    haroldpo6 Veteran Member

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    Yea, I used rpm because MPH is off for now. Went from 2.73 to 3.08 so between 50mph to 60mph is the worst.
    .
     
  7. cadillac_al

    cadillac_al Veteran Member

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    Has the rebuilder heard the noise? You would think he would have some kind of idea what's going on or maybe he could rule out the gears altogether.
     
  8. big gear head

    big gear head Veteran Member

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    2.73 to 3.08 isn't much of a change. Did you use new or used gears? Used gears can be difficult to set up.
     
  9. haroldpo6

    haroldpo6 Veteran Member

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    New gears, and Tony heard the whine, he called and told me what was happening. Said he took it apart 3 times and could find nothing wrong with the set up. I'm thinking china cheap gears. Tony sets up rear ends for the local racing guys. He said he has no clue what it could be. I'll live with it.
    Thanks guys.
     
  10. badazz81z28

    badazz81z28 Veteran Member

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    I’m using US Gear (made in USA). If you change it out look to them
     

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