# 1967 gto BOP 8.2 POSI swap Help



## Jaysando (Jul 4, 2020)

Hello gear heads,
I need some help... I have a 67 gto with an original BOP 8.2 open with 2.93 gears. I was told that all POSI must be used with 3.- - gears. What must I do to get some POSI going. I bought a rear end seal and bearing master kit from original parts place and currently have both axels out of the car... FYI the axle bearings are hard to pull off even with a 12ton press...😫 I have every tool to do this job including checking backlash with dial indicator... but I don’t have the knowledge on what order to do all this. Oil is out and cars on stands. Any help over the next few days is appreciated.


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## PontiacJim (Dec 29, 2012)

Jaysando said:


> Hello gear heads,
> I need some help... I have a 67 gto with an original BOP 8.2 open with 2.93 gears. I was told that all POSI must be used with 3.- - gears. What must I do to get some POSI going. I bought a rear end seal and bearing master kit from original parts place and currently have both axels out of the car... FYI the axle bearings are hard to pull off even with a 12ton press...😫 I have every tool to do this job including checking backlash with dial indicator... but I don’t have the knowledge on what order to do all this. Oil is out and cars on stands. Any help over the next few days is appreciated.
> View attachment 136368


I think someone gave you bad info - so don't ever go to them for further advice.

Check out this site. Looks like they have an Auburn unit for 2.93 gearing - $485.00. Contact the site and get what info you will need from someone who has the correct parts.






Posi Carriers - General Motors - GM 8.2" BOP - Ron's Machining Service







www.ronsmachiningservice.net


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## Jaysando (Jul 4, 2020)

I’m ordering now... 28 spline is correct for my 67 right? If so it’s the one I need


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## Jaysando (Jul 4, 2020)

Alright!!! Bought the 
*GM 8.2" BOP Auburn Pro Posi Differential 28 Spline 2.93-3.23 542099*

If you guys have any procedures(order of operations) that would really help me out. Transmission and rear ends I’m unfamiliar with. There’s not much on YouTube...


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## BLK69JUDGE (Jun 10, 2010)

welcome
thats good the bearings were on tight as that shows that it probably hadnt had a spun race...
did you knock the retainer ring/sleeve off first before pulling the bearing ?



https://www.youtube.com/results?search_query=pontiac+8.2+posi+install


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## Jaysando (Jul 4, 2020)

I was doing what this guy did... 




The bearings that are hard to remove are the axle ones. Even this guy had a hard time with the right stuff. I’m going to put some heat on it tomorrow.


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## Mine'sa66 (Oct 30, 2019)

Jaysando said:


> I was doing what this guy did...
> 
> 
> 
> ...


Sometimes our 20 ton press doesn't get them off. Be cautious with heat, you don't want to soften your axles. When they won't press, we cut them...carefully.


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## Jaysando (Jul 4, 2020)

Mines a66 that’s great info... I took it to Valley Differentials in Stockton and that guy (owner) was amazing... originally I called him and told him I had trouble getting the axle bearings out. I told him I put heat on one... he ask with what and I told him a small propane torch... he giggled and said that’s not enough heat and also that it wouldn’t have damaged them and that he would cut them off and press on the new ones for $40bucks... now to be honest with you, you can’t get shit for $40 in California but that wasn’t the end... he spun the bearings and checked them out and said... to be honest all these bearings come from China now and these bearings will probably outlast any new bearings I put on... he then changed out my pinion bearing and pressed my new bearings on my new posi for $25 in like 5min... that guy is bad ass!!! I’m glad to have met him... I hope one day someone will read this who needs work around Stockton and use him... however I like to learn and do my own work so moving on to setting the preload on my crush sleeve. I have to google that... lol just found this sight with good info.





GM 8.2" and 8.2" BOP Axle Parts, Gears, and Upgrades


Filthy Motorsports carries a wide range of parts, gears, and upgrades for the GM 8.2" and 8.2" BOP axle including ring and pinion sets, rebuilt kits and bearings, differential covers, upgraded axle shafts, heavy duty u-joints, and more.



www.drivetrainshop.com


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## Jaysando (Jul 4, 2020)

Ok... I’m so confused.. excuse my ignorance... first picture is what I ordered... says it’s a Posi... second is what I received today... it says limitedslip differential... so is that the same thing? Part numbers match...


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## Gtowally (Jan 19, 2019)

Yep...same thing


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## Mine'sa66 (Oct 30, 2019)

Jaysando said:


> Ok... I’m so confused.. excuse my ignorance... first picture is what I ordered... says it’s a Posi... second is what I received today... it says limitedslip differential... so is that the same thing? Part numbers match...
> View attachment 136428
> View attachment 136429


Yes, A limited slip unit allows the rear wheels to turn at different speeds in a "limited" fashion. This is what you usually use on the street. The springs inside the unit can be changed out to allow more or less "slip". In a drag car you might find a spool or other type differential which forces both wheels to spin at the same speed all the time. Not good on the street where you might drive through a McDonald's drive through and want the inside wheel on those super tight turns to be able to spin more slowly than the outside wheel.


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## Montreux (Mar 8, 2009)

Re: Removing the axle bearing. 
Use a cutoff wheel to cut a 2 deep grooves in the retaining ring 180 degrees apart. Go as deep as you can without touching the axle. Put a cold chisel in the slot parallel to the axle. Tap lightly with a rubber mallet...sorry...Strike firmly with a BFH, and the ring should split.


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## Montreux (Mar 8, 2009)

Wheel bearings on the 8.2 are not lubed by the axle dope. They are “lifetime lubed”—a self-fulfilling prophesy! When the grease in the bearing goes away, the bearing life is OVER! Also, they are ball bearings, not roller bearings. They have a shorter life.
Replace them.


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## Jaysando (Jul 4, 2020)

Quick update with photo. Diffs aren’t too bad to work on. You buy all the right stuff and you get good results. Just put my pinion in with new bearings... It was a really good 8.2 Pontiac posi install for a Firebird on YouTube that helped out a lot. 



Finished up with 15 foot pounds of rotational torque on my Pinion. Currently checking the backlash.. Back lash done... set at .006.


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