94 Rearend ???

[azkkn]

The first Positraction limited slip differential I had came as one of only 3 options (AM radio, 300HP/327ci engine, Posi) on my brand new 1963 Impala. Subsequent units in my 1966 GTO 389 Tri-Power, 1968 Firbird 350, 1973 Gran Prix 455 HO, etc....... all the way up to my 94 Formula - you get the picture. And I never saw a posi work the way you described.

Currently running an Eaton HD (14-disk) posi, and it will lay down two very dark strips of rubber from the instant you hit the throttle, until you finally let up.

love the shattered carrier in the back ground

[Injuneer]

The problem with the stock 10-bolt is the small 7.50/7.625" diameter of the ring gear. You just can't make the gears strong enough. The carrier is not the problem. The axles are seldom the problem (seems to be more of a problem on the LS1 cars). The housings are "OK". Its the tiny gear set that can't take the torque.

GM has made several 10-bolt rear axles over the years, and not all of them have problems. The earlier models used 8.20" and 8.50" ring gear sizes. The 12-bolt has an 8.875" ring gear. The Ford 8.8" and 9.0" gears are plenty strong. The ultimate may even be the Dana 60, with its 9.750" gear size, and extremely low mechanical loss (5%, vs 7% for the 12-bolt and 10% for the 9-inch). Strange is now making a Dana 60 direct replacement axle for early GM cars. I can't wait until they get around to doing a torque arm mount version for the 3rd and 4th Gens. It will be a way better choice than either the 12-bolt or the 9-inch.

The picture I posted is a story in itself. I got my Strange 12-bolt and installed it myself. Went to install the ABS sensor, and reached in through the hole in the top of the housing to see how far the reluctor gear was away from the sensor hole...... ooooopppppssssss.... no reluctor gear. I called Tom Byrne who I had ordered the rear from, and within minutes he had Strange on the phone, confirming they "forgot" to install the reluctor gear I had paid $300 extra for. Strange sort of wanted me to take the rear back out and ship it back to them, but I wasn't too happy with that.

So.... Strange said they would ship the new carrier to a shop we both agreed on, the shop would install the new carrier and Strange would guarantee the swap. We agreed on a nearby shop that I heard was good (but had never been to), and Strange claimed was one of the best. Took a month for Strange to make and ship the new carrier. I made an appointment for the swap, drove over and pulled the car into the shop. It was like stepping back into history. Guy had a Hemi-powered street rod under a tarp and shelves full of old Hemi components.

I asked him why he didn't seem to have a lot of business.... at the time he showed me a crayon mold he was repairing for a nearby crayon factory, and a spiral powder feeder that he was welding some wear plates onto. He told me that the only people who had money for car mods seemed to be kids with imports, and he wasn't interested in doing that kind of work.

Didn't even have a lift. Jacked the back end of the Formula on the shop floor, managed to bemove the entire carrier without removing as much as the panhard rod, swapped the carriers and reinstalled the new one TOTALLY BY "FEEL".... never measured a single thing. NEVER saw anyone do a rear like that. The setup performed flawlessly for a couple years, and then I swaped out the 3.73's gears for 4.11's. He had more broken parts laying aroung than I had even seen. He also had the opinion that in the basic configuration, the 12-bolt was stronger and more reliable than the basic 9-inch... another unique view. But after seeing his work, and knowing the end results, I have nothing but respect for him. I've gone back to him for some welding work.