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  •  » 8" rearend

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    2/25/2023 10:57 PM  #1

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    8" rearend

    I had my 8" non poss diff (2:79s) rebuilt a few years ago (apx 7000 miles) and it still makes a little noise when you let off the gas? Its not a lot but its there and I can here it if I turn off the tunes?
    I checked the magnetic plug and found it clean. Should I be worried? I now run Amsoil sever 75-110 for lube

    Last edited by Cab4word67 (2/25/2023 10:59 PM)

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     

    2/26/2023 12:28 PM  #2

    BILLY WALTON from GEORGIA
    Carrollton, GA Bash Host

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    From: CARROLLTON GEORGIA
    Registered: 4/14/2013
    Posts: 2,431

    Re: 8" rearend

    My universal joint was going bad and made a noise letting off the gas once and the leaf spring u bolts were loose once and also made a noise.

    Its really me....I fixed my caps lock .
     

    2/26/2023 1:34 PM  #3

    RTM
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    From: Cape Coral FL
    Registered: 5/22/2019
    Posts: 1,711

    Re: 8" rearend

    If they are after market gears and they have made this since they were setup.   You’ll be fine but the noise will never go away.

     

    2/26/2023 5:59 PM  #4

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,849

    Re: 8" rearend

    Prolly the 'best fix' is noisy muffz !
    It lopes like a hot rod.....
    it looks like a hot rod...
    might as well sound like a hot rod !!!
    6sal6

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    2/26/2023 6:27 PM  #5

    Ron68
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    From: Mukilteo, Washington
    Registered: 4/01/2013
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    Re: 8" rearend

    Cab4word67 wrote:

    I had my 8" non poss diff (2:79s) rebuilt a few years ago (apx 7000 miles) and it still makes a little noise when you let off the gas? Its not a lot but its there and I can here it if I turn off the tunes?
    I checked the magnetic plug and found it clean. Should I be worried? I now run Amsoil sever 75-110 for lube

    Once had a n 8" 2.79 pumpkin making that noise - had to carry a little power when moving otherwise if I let off the gas completely it would make noise. Pinion bearing was bad. But if you already had it rebuilt and have 7K on it with new gears then - send it.
     

    68 coupe - 351W, 4R70W, 9" 3.25 -- 65 convertible - 289 4v, C4, 8" 3.00
     

    2/26/2023 7:00 PM  #6

    BILLY WALTON from GEORGIA
    Carrollton, GA Bash Host

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    From: CARROLLTON GEORGIA
    Registered: 4/14/2013
    Posts: 2,431

    Re: 8" rearend

    6sally6 wrote:

    Prolly the 'best fix' is noisy muffz !
    It lopes like a hot rod.....
    it looks like a hot rod...
    might as well sound like a hot rod !!!
    6sal6

    FLOWMASTER 40's

    Its really me....I fixed my caps lock .
     

    2/27/2023 7:05 AM  #7

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,486

    Re: 8" rearend

    In my experience a lot of aftermarket gearsets whine on deceleration.  They are set up correctly, and will go hundreds of thousands of miles, but they just make noise.  If the noise is consistent and has been that way since it was rebuilt I wouldn't worry about it.  If it starts to get worse it would be time to investigate. 

     

    2/27/2023 9:44 AM  #8

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,849

    Re: 8" rearend

    Ya could always put a spool in it !
    Then....ya have a whole new set of issues !
    6sal6

    Last edited by 6sally6 (2/27/2023 9:47 AM)

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    2/27/2023 3:30 PM  #9

    BobE
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    From: White Plains, NY
    Registered: 4/04/2013
    Posts: 2,633

    Re: 8" rearend

    6sally6 wrote:

    Ya could always put a spool in it !
    Then....ya have a whole new set of issues !
    6sal6

    LOL
     

    65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
     

    2/27/2023 5:14 PM  #10

    TKOPerformance
    Hyper FYIFORD ADDICT

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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,486

    Re: 8" rearend

    Ah, just weld the spider gears to the case.  I've got a spare open 8" case I'll donate.  Get some spare axles though...

     

    3/03/2023 5:56 PM  #11

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    Re: 8" rearend

    You guys are great, it was in fact a OEM set, he said he wouldn't use aftermarket. It has never gotten worse and in fact sometimes I don't know its there. I have done the 40s, turned up the tunes and keep my foot in it as much as I can. Should be fine.

    Last edited by Cab4word67 (3/03/2023 5:57 PM)

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
       •Thread Starter
     

    3/05/2023 6:16 AM  #12

    RTM
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    From: Cape Coral FL
    Registered: 5/22/2019
    Posts: 1,711

    Re: 8" rearend

    Cab4word67 wrote:

    You guys are great, it was in fact a OEM set, he said he wouldn't use aftermarket. It has never gotten worse and in fact sometimes I don't know its there. I have done the 40s, turned up the tunes and keep my foot in it as much as I can. Should be fine.

    Were they used or new gears?  If used I would say they weren't setup like they were before or maybe the used gears had a bearing going bad causing and bad pattern and now things are tight.  Either way I think you will be fine.

    On a side note I found an 8 inch axle fore sale and one of the pictures it sure does look like its a trac loc.  If it wasn't almost 3 hours away I would have bought it.  I still may buy it, there's a 65/66 mustang fastback roll bar for sale near that would be on the way to the 8 inch axle.

     

     

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