Just joined? Please introduce yourself.
Results 1 to 5 of 5

Thread: 12 bolt posi noise

  1. #1
    Registered Member Bihili's Avatar
    Join Date
    Sep 2012

    Member #:896
    Location
    outside K. C.
    Posts
    267

    12 bolt posi noise

    I rebuilt my twelve bolt posi with new spider gears, new posi plates and new shim kit from Tom's Differentials.
    http://www.tomsdifferentials.com/

    I watch Tom's you tube video (parts 1&2) before the assembly and it assembled just fine.
    https://www.youtube.com/watch?v=CGq15JBBUQw

    The twelve bolt has 500 miles on it now and it clicks and sometimes catches when turning .
    I have put in two bottles of posi additive and it helps but did not cure my problem.

    The shims are too tight on the posi plates and creating the problem. It is not a terrible problem but annoying.

    Will it get better with more miles on it or should I change shims?
    Bill 1957-427-177-6-410

  2. #2
    Registered Member
    Join Date
    May 2012

    Member #:625
    Posts
    3,409
    Quote Originally Posted by Bihili View Post
    I rebuilt my twelve bolt posi with new spider gears, new posi plates and new shim kit from Tom's Differentials.
    http://www.tomsdifferentials.com/

    I watch Tom's you tube video (parts 1&2) before the assembly and it assembled just fine.
    https://www.youtube.com/watch?v=CGq15JBBUQw

    The twelve bolt has 500 miles on it now and it clicks and sometimes catches when turning .
    I have put in two bottles of posi additive and it helps but did not cure my problem.

    The shims are too tight on the posi plates and creating the problem. It is not a terrible problem but annoying.

    Will it get better with more miles on it or should I change shims?
    I have had same same results and cured it with GM gear oil or Chevron Delo 80w90 plus GM posi additive. Penazoil and other crap brands from ORileys have caused me issues in the past, even with additive. I have posi-track diffs in over a dozen cars and trucks and have found them sensitive to lube quality.
    Last edited by markm; 09-16-2014 at 09:08 AM.

  3. #3
    Registered Member Maddog's Avatar
    Join Date
    Aug 2012

    Member #:777
    Posts
    1,324
    It's common for a rebuilt posi to make loud noises. I had one that sounded like it was going to explode, had all the correct oil and GM whale additive. It takes some time for the plates/discs to get lubricated. Try going real slow and make constant sharp left and right turns to get the oil into the plates etc. Mine stopped making noise after I did this. Good luck.

  4. #4
    Registered Member JT56's Avatar
    Join Date
    Mar 2013

    Member #:1608
    Location
    DFW Texas
    Posts
    1,209
    I run valvoline in my stuff and its been good to me. Whether its been a corporate 14 bolt, Dana 60 and Dana 70 HD or 9".

  5. #5
    Registered Member
    Join Date
    May 2012

    Member #:625
    Posts
    3,409
    Quote Originally Posted by JT56 View Post
    I run valvoline in my stuff and its been good to me. Whether its been a corporate 14 bolt, Dana 60 and Dana 70 HD or 9".
    My 12 bolts in 67 Camaro, 72 Cheyanne and 72 K/5 Blazer or the Posi in my C3 Vette are more sensitive to lube quality then the Power-Locks in the Dana 60s in Camaros or my 55. The 10 bolts in my 85 Cutlass [7.5] and 8.5s in 74 Z28 and both my 87 GMCs are somewhere inbetween. This makes sense because the posi units in the trucks came out of 70 era Camaros.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •