8 3/4" 741 why this happen

[dartswinger84]

741 case, i'm not sure about lock type, is it oem or aftermarket part, i think it's oem. But it looks like this, why exactly?? It runs great, no klinking klankin sounds, ring&pinion is tight, not loose at all. Is it two-piece track lock-sure grip?

 

[360DartGT66]

That looks like a material flaw to me. Loss of hardening. Maybe from overheating due to low lube level?

I'm guessing here, in no way a diff expert.

 

[AJ/FormS]

That happens a lot to that cone-type SGs. It usually starts when the cones bottom out and you start doing one-wheel-peels. Yours is nearly the worst I've ever seen. I've had some of those repaired over the years, but I think yours is done. Once you get it apart, I think the guts will be done-for too.You're probably lucky, cuz they occasionally spit the pin out, before it gets that bad. Ima thinkin at least one spider is welded to it. Yup, one-wheel-peels will do that....
If you're running a BB, I think it would be time to upgrade.

 

[crackedback]

That's junk...


The spider gear froze to the pin and twisted the pin. Common issue with that style of sure grip.

 

[dartswinger84]

Oh nice. I have a 742 case with posi lock, i will put it in.
Thanks crackedback and AJ/FormS

 

[dartswinger84]

Couple of pics more.
That cross shaft slot or groove, what ever it is, was 1.46" another side and 1.41" another.I think it should be around 0.800"?? Cross shaft -> case gap was 0.55". Another pinion on cross shaft was tight and another was loose, and looks like there should be lock pin in cross shaft, but i cant find it??? Junk #-o