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
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!
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
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.
oph 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
Jim, 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? :3gears: Roger
thanks 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 .
any thing Hi roger did you come up with anything on the 28 spline measuring??? o No: Jim with the odd ball posi.
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 .
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