[pontiacjeff]

Hello everyone. I currently manufacture and sell the only clutch-type, pre-loaded limited slip differential available for GM Front Wheel Drive cars. My "Engineered Performance Limited Slip Differential" has been in use for 10 years and proven on the street, some over 100,000 miles, over 500hp on slicks, drag-raced, road-raced, and circle- and oval-track raced on asphalt, dirt, and even ICE! The same unit has been used extensively in the transverse mounted RWD Fiero with excellent results!

Some of you know me and my experience with the big P-axle. I have been building and racing the "12-bolt rear with the 10-bolt cover" for 20 years. I also rebuild and install gears and differentials in any/all GM cars and trucks. One thing most guys fear about doing a posi swap is the cost involved with paying someone with the proper tools to install it!

That's why I have decided to apply my experience with the FWD differentials to the RWD GM (corporate) 8.5" rearend and offer a drop-in limited slip conversion for the STANDARD OPEN differential. It will be a DIY kit that the average guy can install with hand tools in an afternoon. It utilizes sintered bronze clutch discs, CNC-machined and heat-treated preload plates, and application-specific pre-load spring rates (adjustable to suit driving needs!!!)

I am building the first unit right now. The prototype will be in a car by the end of September. This is not a Mickey-Mouse effort. This is a REAL clutch-type, pre-loaded, limited slip assembly that utilizes STOCK OPEN spider gear sets. It will fit ANY 2-, or 3-series OPEN differential with 28-spline c-clip or the later 30-spline as well. It functions JUST LIKE A FACTORY LIMITED SLIP (POSI)!!!!

Any and all questions or comments are welcome.

[boater bill]

I have read your posts on your posi conversions for the big car. Very impressive for sure.
Do you have something like that for the 8.2 Pontiac rear? I have a 3.23 open rear that is working well until I launch even a little bit hard. Then it's one tire smoking pretty heavy. OK, real heavy with my 461.
I like the idea behind the Powertrax locker that replaces the side and spider gears. I'm guessing yours will be similar.

[67drake]

Cost?
Also,does this take the place of the stock carrier,or do you use your current open carrier,I'm not clear on this?

[pontiacjeff]

I will be offering this same conversion for the 8.2 Pontiac as soon as I can get y hands on a core differeni

[pontiacjeff]

The powertrax is a ratcheting locker and afaik not available for the Pontiac 8.2

[pontiacjeff]

The conversions I am going to offer utilize the stock open differential housing. And it DOES NOT REQUIRE REMOVAL OF THE CARRIER FROM THE REAREND HOUSING!!!!

[pontiacjeff]

The cost is projected to be less than a new Eaton or Auburn posi. AND its a DIY not requiring any bearing installation or costly shimming setup.

[TinInjun]

Originally Posted by pontiacjeff

I will be offering this same conversion for the 8.2 Pontiac as soon as I can get y hands on a core differeni

Jeff, I have a 8.2 you can have.

[pontiacjeff]

Originally Posted by TinInjun

Jeff, I have a 8.2 you can have.

Sweet! I'll send you a pm with my address and give you some $ for shipping via PayPal.

[frankyboy455]

Originally Posted by pontiacjeff

I will be offering this same conversion for the 8.2 Pontiac as soon as I can get y hands on a core differeni

Now that is really great news. My guess is that you'll sell quite a lot of those.

[pontiacjeff]

I like the idea behind the Powertrax locker that replaces the side and spider gears. I'm guessing yours will be similar.

The EP-LSD utilizes stock spider gears. The parts are installed in the stock carrier and convert the operation from std open to positive locking without the chatter and clunk associted with ratchet type inserts.

[Scarebird]

Jeff, did you need a carrier or the whole diff for the 8.2 BOP?

[pontiacjeff]

Originally Posted by Scarebird

Jeff, did you need a carrier or the whole diff for the 8.2 BOP?

Just a carrier with the gears in it. Any series.

[pontiacjeff]

Scarebird, let me clarify. All I need is a differential carrier assembly. I do not need a complete Rearend housing or ring & pinion gears.

[Brian Hummell]

[Scarebird]

Good.

I have a 3.23 open carrier, - no gears.

Contact me by direct email if you want it. Just cost of shipping.

[pontiacjeff]

Originally Posted by Scarebird

Good.

I have a 3.23 open carrier, - no gears.

Contact me by direct email if you want it. Just cost of shipping.

Thanks Scarebird, but TinInjun is bringing me on 8.2 on Wednesday next week! Ill have it prototyped by the 15th of this month! Who wants to be the first to try it in an 8.2??? Send me a PM. I'm going to pick up a 73 Ventura on Saturday. Russ will be the first 8.5" recipient. (His is a 3.23 open taken from a later model firebird or something.)

[se428bandit]

Originally Posted by pontiacjeff

Thanks Scarebird, but TinInjun is bringing me on 8.2 on Wednesday next week! Ill have it prototyped by the 15th of this month! Who wants to be the first to try it in an 8.2??? Send me a PM. I'm going to pick up a 73 Ventura on Saturday. Russ will be the first 8.5" recipient. (His is a 3.23 open taken from a later model firebird or something.)

My Ventura is at Jeff shop and we are hoping to hit the dragstrip this weekend. I have been looking for a 8.5 posi for my car for a year. I have been running ads on here and Craigslist with not even a call so this is great news for me.

[F ROCK]

this sounds awesome!
i'd be interested in the 8.2 version.

[madokie]

while this is good news anytime more parts are avalible for our Pontiacs, their is still a HP limit envolved here. the stock carrier is what 40 -50 years old??? while it certainly will hold up just fine on most street cars,with stock tires and a auto-trans,its a only going to take so much abuse at a 1/4 mile dragstrip with slicks and a 4-speed,so use it accordingly folks, the mustang 5.0 folks found this out the hardway back in the late 1980's, adding more and more power till the stock carrier and its gears blew up, destroying the rear axle in the process,no biggy they just went to nearest junkyard and got another 8.8 axle with factory posi and had at it, still plenty of 5.0 rear axles around too, but we only have so many axles left for our Pontiacs,so lets not destroy any more than neccesary.