rear differential gives it's all

[Mike R.]

Re: rear differential gives it's all

Hi Gary. Curious, what is the difference between first and second generation main bearing caps (both functionally and visually)?

THanks

Hi guys,Brad & Bob.

I'm not going to turn this into one of my tech threads as some may think I'm doing it for my own purposes. I will be glad to answer any questions you have if you contact me.

I will make a couple of points here though. Sounds like someone was pointing you in the direction of a new loaded Eaton posi, not what I'd use in my vettes.
1- I never use fiber clutches, I wouldn't use them in a go-cart let alone a vette. Look at my pictures of them on Digital corvettes and you'll see what I mean.
2- I know Tom Watt and do the 12 bolts builds now as well as what I coined as a super 10 bolt a few years ago. You can find my thread on these jobs on DC as well
3-I never build any Eaton posi for c2- c3 with springs or plates. I machine fit them to work without them and they work better with less wear and no hammering. I believe I'm the only one building them like this. Both Brad & Bobs diff's are setup like this.

Looking at your picture I see it's an early diff with the 2nd design bearing caps and stock bolts, the case is probably wrecked,ARP bolts with washers. I use ARP as well only I do not use washers with them in the vette build. I went over this with ARP a few years ago and they do not recommend the washers. I never use stock cap bolts and fit every cap to my spec's or fit a steel cap.

Anyway if I can help you with any questions just give me a call.

[Gary R.]

Re: rear differential gives it's all

There were 3 designs on the 63-79, that I'm aware of and I think I've rebuilt every year diff in this range.
The 63-64 use a "flat" rough cast cap, then 65-70 used the ones shown, 71-79 were similar only have a cast in tab over the shim.

Here is a 64


Here is one of super 10 with a steel cap and the 65-70 cap on the RH


Here is a 71-79, this particular one was so bad I was able to remove the springs with my fingers.

[James G.]

Re: rear differential gives it's all

"The toms that I'm thinking of is in idaho. tomsdifferentials.com It's been afew years since i've had work done there so I'll call first. It is a road race car."

Tom moved from California about 5 yrears ago. He was "the Man" in the 60's thru late 90's. Built all the differentials for Guldstrand, Traco and other racers of Thunder Alley.