Weird diff failure

[Aircooled]

I made it to 125k miles with the stock 7.5" rearend on my 6spd, LS1 Formula. Here is damage pics. Anyone ever seen a failure start out this way?

PS: I tried to annotate each picture, but can't seem to do it that way any more:

First pic is the diff cover that greeted me.
Second pic is this little gem I found rolling around inside. It's about 3/4" diameter.
Took me a long time to figure out where it came from. It was the head to one of the bolts that hold the Torsen together. (third pic)
4th pic show the damage to the inside of the housing as the bolt head worked its way into a sphere using the ring gear as a hammer.
5th and 6th pics show the secondary failure of the diff case as the bolt head (circled in blue) continued to get wedged in the spinning parts.
7th and 8th pics are come close up of the fracture surfaces.

[Brian Lohnes]

That musta sounded awesome. Yikes!

[squirrel]

I had a ring gear bolt fall out of a 12 bolt truck rear....poked a hole in the cover, made some fun sounds, but didn't really hurt anything. I'm impressed that yours failed that way instead of how we'd expect it to...by taking all the teeth off the pinion or something

But I'm not liking the fact that the Torsen came apart....how common is that?

[tardis454]

Common problem in 7.5/7.625's, GM 8.5's do it too.. Usually the shims wear out & the carrier walks around in the housing.
We sell EVERY F-Body, S-10 P-up/Blazer rearend because of that... & EVERY Fullsize Chevy 8.5 too.

[CTX-SLPR]

Well that settled it between the Torsen T2 and the Detroit TrueTrac for my 8.5...

[oldsman71]

sorry to see that!! breaking stuff sucks!!! my 7.5 spider gears are what seem to go first, my auburn posi trac hasnt had much more than
300 hp and 245 60 15 cooper cobras so it hasnt been tested too much yet.

[Scott Liggett]

get a bearing support cover for the next diff. There are set screws that prevent the bearing caps from moving around.

[oldsman71]

get a bearing support cover for the next diff. There are set screws that prevent the bearing caps from moving around.

I was thinking of getting one from jegs

[Scott Liggett]

I'm going to get one for my 12 bolt when I install it.

[Aircooled]

get a bearing support cover for the next diff. There are set screws that prevent the bearing caps from moving around.

That wouldn't have helped in this case. Once that 3/4" bolt head was rolling around in there, the diff's fate was sealed.

[Stich496]

That wouldn't have helped in this case. Once that 3/4" bolt head was rolling around in there, the diff's fate was sealed.

the cover might have helped as the parts wouldn't have been able to move around stressing the bolt..

[milner351]

That must have made some horrible noises - how long do you think that bolt head was getting beaten around in there?

That is not a failure I've ever seen before, yikes.

[Aircooled]

That must have made some horrible noises - how long do you think that bolt head was getting beaten around in there?

The bolt head only had 2 miles to do its damage. It was 11pm when it let go and I choose to press on the remaining 2 miles to the house. Sounded like (and felt like) someone was randomly wacking the back of the car with a 20lb sledge hammer.

[Eliteman76]

I distinctly recall years back in my stepdad's '85 silverado, mom went through deep water one time in a local flood, and it filled the rear axle full of water.
She was driving home, and I heard like 5 blocks away teeth being shears off the ring gear TING TANG TING TINK TING

[milner351]

Only two miles - amazing - imagine what that thing would have looked like if it let loose at high speed.... wow...

In the grand scheme of things - you got lucky it broke so close to home, but it still sucks that it broke.

Can you re - use the housing with a new differential and cover - or are you going to upgrade to a different axle now?