BOP 8.5 axle endplay

Daniel828
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BOP 8.5 axle endplay

Postby Daniel828 » Fri Jul 25, 2014 7:26 am

Hi jim,
We spoke on the phone yesterday about axle endplay on a 71-72 gm 8.5. Mine is a buick unit going into a 66 cutlass. My concern was the endplay. The drivers side was .020 and the pass side was .040. I did a little reading on the web yesterday and there not much info out there about endplay in these units. Some ford 9" guys use shims to take up endplay. So, i had a bunch of pinion shims lying around so i made a cut in them and placed them between the retaining plate and seal. I have zero play on drivers and about .005 on the pass side. What problems may occur with this?
Thanks
Dan

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monzaz
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Re: BOP 8.5 axle endplay

Postby monzaz » Sat Aug 02, 2014 2:02 am

If the shim slips up or down it may tear up the seal. Other than that I do not see a problem. WE are working on shims that go into the axle tube to move the bearing outward which in turn will make the seal outward and again with the correct shim make contact with the retaining plate.

REASON this is all happening. The seals in the World along with all the bearings etc. are NOT BEING manufactured to correct specs...WHY? who knows. Someone got the wrong specs or they got mixed up etc. It seems NO MATTER whos parts we buy they are all wrong for the A9 bearing and the 2146 and 712146 seals

So this is what we have to do to solve the worlds ignorance to making the correct parts. :( Jim Mitschke

J D Race
J D Race

Daniel828
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Re: BOP 8.5 axle endplay

Postby Daniel828 » Mon Nov 03, 2014 9:16 pm

Hi Jim, I'm still chasing down this endplay issue. I was wondering what the dimensions of the original style axle bearings are? Someone suggested that maybe a later model full size GM car with an 8.5 rear may have the correct size? I found a place online that has the bearing, but they are expensive and I don't know the dimensions. They look like the originals though
Many thanks
Dan

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monzaz
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Re: BOP 8.5 axle endplay

Postby monzaz » Fri Nov 07, 2014 10:11 pm

There could be end play from the bearing itself and then there could be end play from the axle seal not being the correct thickness. Bearing end play is fine as long as the seal thickness is correct. Some are 712146 seals .490 thousands thick and 2146 seal is .460 thousand thick
J D Race

Daniel828
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Re: BOP 8.5 axle endplay

Postby Daniel828 » Thu Jan 22, 2015 2:14 pm

Hi Jim
Still having endplay issues. My unit has a used eaton posi in it. I've tried shimming the axle bearing races, but still have endplay. .020-.030ish on both sides. I've read that I can shim and or replace the clutches in the eaton posi to help with endplay. Does this only apply to c-clip axles?
I don't know why this is bothering me so much. The old 8.2 I took out has zero endplay and is so smooth. That's what I'm comparing to
Thanks
Dan

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monzaz
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Re: BOP 8.5 axle endplay

Postby monzaz » Thu Jan 22, 2015 7:38 pm

I will tell everyone this ALL THE bearings for the GM oiled bearings axle system are NOT CORRECT.... The seals are not correct and the bearings are out of spec.
THERE IS NOTHING we can do about any of this.
This is caused when people do not care about what they build and it is a darn shame. Sometimes we find a slew of seals and bearings better than other and hoard them up ....Lately that is NOT happening. OLD L & S seals and bearings were good - Green Bearings were good. BUT these companies have been out of business for 15 -20 years now. :(

Have you driven the car yet?
Have you determined if it is the BEARINGs between the press on race or the seal being too thin OR is your housing machined 90 degree lip dented in or worn?

Pictures of the inner tube bearing and seal ... etc.

Your Posi unit will have NOTHING to do with the end play on a bolt in axle. ONLY c-clip and even then you can only shim so far on the c-clip axle because you have to be able to get the spider end play in and correct.

The 8.2 was WHAT year? Sealed bearing or oiled bearing? Jim
J D Race


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