Earlier this year my son Steve and I did a rearend for a fellow forum member. He went basically factory stock parts. The posi clutches were $175 and the axles shims were $110 from the factory. We need the shims to tight up the spider gears and help fix the end play problem with brand new yokes. Taking free play out of the clutch pack takes play out of the side yokes. We removed .050 free play by just shimming up the posi unit properly. This leaves the spider gears with very little free play. We do NOT use the posi springs.

Anyway we did the rearend according to Gary's instructions and it was a good learning experience for my son and myself. I have done dozens of rearends over the years but Gary taught me new things.

Anyway I we were doing another rearend for a forum member using Gary's posi kit with included all the posi clutches and the axle shims.
First thing you notice is the extremely heavier clutch plates. The stock factory ones are like your fingers, Spread your fingers and look at all the gaps between them. This is the factory style. Lots of open area and reduced area. Gary's are completely solid, far more area and look alot beefier. Remember you are not using springs but properly shimming side gears for posi engagement and yoke end play. I will definitely go with these in future.
The next is the axle shims. While the factory kit for $110 consisted of a number of .010 shims Gary's consisted of 2 carefully marked .010,.015,.020,.025,.030,.035,.040, and .045. Each marked and 2 of each. A very nice kit.

We went for Timkon bearings and a complete set was $86 CDN. Seals I don't know the cost yet but my son has them.

We powder coated the housing black but the paint looses the bright gloss that powder coating normal puts on because oil must come out of the casting when heated in the oven. It is durable but not extremely bright.

Gary you put together a really nice kit along with instructions

 

Gary does have some nice kits and does good work too.

Whenever we powdercoat diffs, we always throw them in the oven 1st, than wash them down w/the correct chemicals and put it in the oven once more before we put any powder on it. We have a 30 ft oven and do lots of frames too.

 

How much do you charge for powder coating the frames, and do you clean/blast them first? I am across the bay from you in Riverview.
vic

 

who could do this service on my diff ? vansteel? very interested in the posi upgrade

 

GTR1999 send him a PM, His work is awesome. I am also a customer of his
He is a forum member

 

will give it a try

 

Vansteel has my buisness for sure he has been great help to me. When I get everything out my differential is going to him to up grade yokes, gears,stub axel flanges, halfshafts, and posi unit.

 

Acid Dip $650
SandBlast $400
Powder Coat $550

Sanblasting is not really sandblasting. We use really fine bark wood. Sold DuPont. Sandblasting will etch the frame and this stuff won't. The finish is much nicer(smoother) and it cleans better in my opinion.

 

Acid Dip $650
SandBlast $400
Powder Coat $550

Sanblasting is not really sandblasting. We use really fine bark wood. Sold DuPont. Sandblasting will etch the frame and this stuff won't. The finish is much nicer(smoother) and it cleans better in my opinion.

 

Acid Dip $650
SandBlast $400
Powder Coat $550

Sanblasting is not really sandblasting. We use really fine bark wood. Sold DuPont. Sandblasting will etch the frame and this stuff won't. The finish is much nicer(smoother) and it cleans better in my opinion.

 

Thanks for the compliments guys.It's my pleasure helping out fellow vette owners.

Red- if I can help let me know.

Gary

 

Thanks for the compliments guys.It's my pleasure helping out fellow vette owners.

Red- if I can help let me know.

Gary

 

Thanks for the compliments guys.It's my pleasure helping out fellow vette owners.

Red- if I can help let me know.

Gary

 

Sorry for the double post,when I replied the forum wasn't working right.
Gary

 

VANSTEEL and VB&P do great work, but in a (get it in n get it out way)
GTR1999 takes his work to the next lever since he is not running a shop
with high production #'s. Ask anyone who has work done from him

If I can get AWESOME work cheaper, then call me a CHEAPIE
My axel's and rear diff, are next for him..

 

Norval & Gary, Every posi unit I owned failed in the same way. I don’t think what your doing would helped me, but I may be wrong.

Every failure I ever had appeared during WOT and during a turn. Whether it was on a track or on a freeway on ramp.

The pin that goes through the case would elongate the case hole to the point where the pin would be ripped out of the case and crack or break the case housing.


The only fix I've found is the polished cases with the larger pin diameter.

 

And where do you find those

 

I was breaking a posi just about anually with high 3000 rpm stalls and sticky big tires. Lots of 7000+ rpm shifts.

Toms differentials and @ $700 and I've had this posi unit for over 4 years.

 

Not bad at all

 

Gkull, yes I'm aware of the center pin failure.I'm glad you asked about it. It's one of the things to check when rebuilding a posi,either a 10 or 12 bolt.It is more common on a 10 bolt, like the corvettes have. I believe I addressed that in my paper, but I'll double check it.

If the hole is in good shape then you can still use the carrier as most shops do. I have used some with pinion scarring and they still hold up.

Keep in mind too that I'm talking about street cars with street tires. When guys ask me to rebuild a differential I always ask how they plan on drivng the car. For a street car I'm completely confident my setup works, no question. Now if you add 500,600, 700+ hp, sticky tires and push it no doubt something will break.Like any of the performance parts companies, I can't guarantee heavy use race parts will not fail. The pin,spiders,or even gear may break under such circumstances.Of course the ujoints or even 1/2 shaft will go too. When asked about this application I always recommend the 12 bolt conversion-which has the large carrier,gears, and pin. I prefer to build street type differentials vs the all race type.

The stock 3-series corvette carrier can be fit with the larger pin from a 12 bolt and that requires 12 bolt spiders as well. The carrier can be machined and bushed for the larger pin. In most cases this in not required for a street corvette. As with the advertised rebuilds I only see this offered by Tom's or Van Steel, with the assoicated costs. Also keep in mind that Tom sets up the 12 bolt posi the same way-radiusing the edges,springless with the correct shimming. So the difference comes down to the larger and stronger carrier,pin, and spiders. When you add this option to the general rebuild it's just about prices them out of the range most guys with street cars want to spend for a car that sees 1,000 miles a year.

I believe most shops will install a new Eaton when they find one with a egg shaped hole. Danny may add more light to this also,but the cost of doing a 12 bolt posi conversion is more then just installing a new Eaton. I'm not saying it's a better install,just much faster and more profitable. Most guys will not push their cars to the extremes you do.

I hope this sheds more light on the matter and the inherent weakness of the Eaton. It's still one of the best carriers used in a production car.But to be fair we have to compare the way they are rebuild and the intended usage.

I think it's good you brought this up, I know it and took if for granted most others do too. I'm sure it will help inform many more guys on the options when they get to the point of considering a rebuild.




Gary