on going 8.2 question for oph

Discussion in 'Got gears?' started by monzaz, Sep 10, 2004.

  1. monzaz

    monzaz Jim

    on going BOP 8.2 question for oPh and axle size

    I have that 8.2 B.O.P. positraction did recount the splines and it does have 28 splines... Question is - Does that type of rear have smaller diameter 28 spline axle then the chevy type? I thought 28 spline was 28 spline and 26 was 26 did they make 2 different 28 spline diameter gm rears??? I can not measure the axles that this rear used because I do not have the whole rear just the posi unit I got at a swap meet. I can mesure the diameter of a chevy type axle I deal with these rears more. Thanks again and I did not know how I came up with 27 splines must have had a long night that day he he. lol sorry about the confusion but would like to know what this thing is to fit so I can look out for that type of housing. Jim
    Last edited: Oct 2, 2004
  2. pxtx

    pxtx Member

    Jim, I know you do enough axle work and I have to concure. As far as I know a 28 spline is a 28 spline. There are some aftermarket "special" splines which don't work with OE style spline but if it is stock- a 28 spline is a 28 spline. I've even used Ford axles with GM posis!
  3. monzaz

    monzaz Jim

    28 spline

    So I have two of these posi units and the people I got them off of said they are BOP posi units 8.2 . I did count the splines and they are 28 but they are a smaller diameter than a chevy axle spline. So any clue by anyone??? Looking for that expert oph somewhere in the world. Do appreciate the the comments. I know an 8.5 is the same as a 8.2 chevy but ido not work on BOP bolt in axle units . The one tempest rear I do have is an 8.5 which really through me for a loop. It was in a 1970 Monte Carlo with a scalloped cover which I thought were mostly 8.2... So here I am????????? Jim
  4. 70 gsconvt

    70 gsconvt Silver Level contributor

    I was told, in regards to splines, that splines are splines. The more splines the thicker and stronger the axle. I think they go all the way up to 40 or so in extreme racing applications.
  5. monzaz

    monzaz Jim


    anyone know i think its roger(oph) could you let him know of this . I can not get the numbers off the castings because the casting imprints are not very good. They sure look like 8.2 BOP rear posis but I do not have any complete rears to get axle from to see if they fit?? Jim
  6. oPh

    oPh Well-Known Member


    Hello, regret being slow in response. My main computer is back up (new keyboard & new harddrive).

    Will have to measure various 28 spline bolt-in axles in the rack. Do know there are different diams of 28 spline bolt-in axles.

    Can you post a link to pic of this carrier?

  7. monzaz

    monzaz Jim


    Alright your back... It is the same carrier you saw before. That one I got a the swap meet and now I ran into another. I counted the spline very carefully and it is 28 spline NOT 27 like I thought But it is a smaller diameter spline then the chevy 28 spline looks just like a BOP posi bolt in axle type I just want to be sure because I do not have that type of rear in stock to check an axle . Hope you can help. Thanks, Jim

    It is the one with the GMC gear and number with left hand thread bolts .
  8. monzaz

    monzaz Jim

    any thing

    Hi roger did you come up with anything on the 28 spline measuring??? :confused: :Do No: Jim with the odd ball posi.
  9. staged70

    staged70 RIP

    I had a problem with this when I removed a rear from a 71 8.5 bolt in and I had other 28 spline axles . I think the posi I had from the 71 might not be correct because of the cone style posi unit . Anyway I wanted to use a set of axles from a 72 with better bearings and they did not fit even though they had the same spline count . The axle may not be buick . It has bolt in axles and may be from a Pontiac or Olds ? It is now in Terrys Suncoupe and has lived for 12 years with no problems . Oh yes I had a local rear end specialist machine the cone flats and install new Olds springs in it .
  10. gsx1970

    gsx1970 1970

    70,455 fan shroud

    John, You wouldn't happen to know where I could pick up a original 1970,455 fan shroud would you, sorry to bother you , but someone said you were the guy in the know. Fred Braswell

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