8 3/4 Rear End - Is this normal?

[dspur]

Have rear end apart to basically restore and replaced pinion seal etc.

No idea why I haven’t observed this previously but is this normal? Doesn’t look normal to me but there were no obvious issues, all moves freely etc.

Ready to put back together until I saw this. I am no rear end expert.

TIA

 

[MWbirdLOVER70]

Have rear end apart to basically restore and replaced pinion seal etc.

No idea why I haven’t observed this previously but is this normal? Doesn’t look normal to me but there were no obvious issues, all moves freely etc.

Ready to put back together until I saw this. I am no rear end expert.

TIA

View attachment 1906572

Saw something like that in the 80’s and my pinion nut came lose and the the car came to a sudden stop doing 30mph and I did a donkey Kong to the steering wheel

 

[dspur]

Saw something like that in the 80’s and my pinion nut came lose and the the car came to a sudden stop doing 30mph and I did a donkey Kong to the steering wheel

Pinion nut is replaced and tightened as far as it will go with Milwaukee impact. Not sure if it is 240 - 250 ft lbs tho, don’t have a torque wrench that goes that high.
Also replaced pion bearing and seal. Nothing is hitting now, wonder if it was the old bearing worn, tho it didn’t appear to be bad. ‍

Oh it is a 741 case

 

[Kern Dog]

You aren't supposed to just ram the pinion nut down to the maximum setting! You may have now just crushed the front pinion bearing.

 

[R413]

That happens when the pinion nut comes loose while driving. Acceleration pushes pinion forward, coasting pulls pinion backwards and it hits the differential if the nut is loose enough.

Was it there before or did this just happen?

 

[Darter6]

You aren't supposed to just ram the pinion nut down to the maximum setting! You may have now just crushed the front pinion bearing.

If it is a 489 case with a crush sleeve used to set pinion depth. But a 471 or 472 you will be ok at 240 minimum .
Common problem with a 489 case.

 

[Fran Blacker]

Given a center section that had those marks from broken pinion, the pinion threaded broke off.

 

[themechanic]

Pinion nut is replaced and tightened as far as it will go with Milwaukee impact. Not sure if it is 240 - 250 ft lbs tho, don’t have a torque wrench that goes that high.
Also replaced pion bearing and seal. Nothing is hitting now, wonder if it was the old bearing worn, tho it didn’t appear to be bad. ‍

Oh it is a 741 case

Harbor Freight has them. Or, maybe try renting from an auto parts store.

 

[Darter6]

pinion nut came lose

First time was a 69 Road Runner back in 1973 for me.

 

[dspur]

You aren't supposed to just ram the pinion nut down to the maximum setting! You may have now just crushed the front pinion bearing.

Actually I did not. Had marked it by scratching the nut and case. Lines up with the same threads showing (not much) as before. My impact isn’t that strong.
Everything moves freely. I’m certain it isn’t too tight, a little concerned it isn’t torqued enough.

Given a center section that had those marks from broken pinion, the pinion threaded broke off.

There was nothing broke unless from a previous repair from way back. That is possible as the case had been welded up, apparently cracked.

Harbor Freight has them. Or, maybe try renting from an auto parts store.

I’ll check on both. Thanks.

 

[dspur]

If it is a 489 case with a crush sleeve used to set pinion depth. But a 471 or 472 you will be ok at 240 minimum .
Common problem with a 489 case.

741 case

 

[OMTWF-72SE]

My bet is the case cracked when the pinion let go and they decided the outside of the carrier didn't matter. But I know I wouldn't use a welded 741 case if I only lived 2 hours from Stephen's Performance.