Pinion bearing 8.75 742

[67charger383]

Is there shims under the bearing on the pinion?

 

[R/T Boy 67]

Yes. That is how the pinion depth is set, assuming you mean between the bearing and the gear head.

 

[1 Wild R/T]

I think the shim is between the cup & the case not between the race & the gear....

You can put a shim in either location & have the same effect... Honestly I don't know why the shim isn't always placed between the cup & the case it would be so much easier....

 

[1 Wild R/T]

I think the shim is between the cup & the case not between the race & the gear....

You can put a shim in either location & have the same effect... Honestly I don't know why the shim isn't always placed between the cup & the case it would be so much easier....

Ok, I just went & checked, 742 uses a shim between the gear & bearing cone.... Dana & 9 1/4 use shims between the cup & case...

741


742


9.25 & 9.75

 

[493 Mike]

Some of the 8 1/4s can have shims in either spot but, I've always found the pinion shim between the gear and bearing in the 8 3/4. It is an inconvenient spot!
Mike

 

[67charger383]

I got the bearing installed and used the right shim.

 

[T2R9]

If you set them up on occasion its handy to have a spare bearing honed out to slip fit on the pinion to determine the correct shim thickness then press the new one on once you have the setting you need.

 

[Cranky]

If you set them up on occasion its handy to have a spare bearing honed out to slip fit on the pinion to determine the correct shim thickness then press the new one on once you have the setting you need.

Doing it that way really makes things easier......especially when you are starting from scratch.

 

[69L48Z27]

Pinion depth is set by shim between the big bearing and the gear. Pinion bearing preload is set with shims under the front bearing and pinion shaft where it seats.

 

[1 Wild R/T]

Pinion depth is set by shim between the big bearing and the gear. Pinion bearing preload is set with shims under the front bearing and pinion shaft where it seats.

But you can set pinion depth with a shim between the inner pinion bearing cup & the case.. It does exactly the same thing..

 

[Cranky]

But you can set pinion depth with a shim between the inner pinion bearing cup & the case.. It does exactly the same thing..

done it that way too.

 

[69L48Z27]

But you can set pinion depth with a shim between the inner pinion bearing cup & the case.. It does exactly the same thing..

On a 742 shim goes between the rear (inner) bearing and the pinion head. No idea how you would do it the other way? Are you saying take the bearing race out and shim that? That would change the bearing preload possibly into a range of not being adjustable. Not sure how or why you would do it any other way than the factory did it.

 

[Cranky]

On a 742 shim goes between the rear (inner) bearing and the pinion head. No idea how you would do it the other way? Are you saying take the bearing race out and shim that? That would change the bearing preload possibly into a range of not being adjustable. Not sure how or why you would do it any other way than the factory did it.

Sometimes the lack of proper shims will dictate how it's done. And if you get the right pinion depth, it shouldn't make any difference in the preload setting shims needed. You move the pinion with a shim under the rear bearing or under the race. Either way, you end up with the correct pinon depth.

 

[1 Wild R/T]

Actually it will effect the bearing preload, just like a shim in the usual spot between the pinion gear & the cone will effect the preload.....

So just like normal you change the preload shim the same amount as the pinion depth....

There's more than one way to skin a cat.... If you don't have a proper bearing puller or a set-up bearing removing the cone will damage it... Removing the cup won't, so adding shims there is a safer option..

 

[69L48Z27]

I don’t own a puller or a press. Took the old pinion to the machine shop, asked to pull the old bearing. $10 later they were separate. Took them home and honed the bearing, now I have a setup bearing. Set the rear up and took the new bearing and warmed it to about 200* in the oven, put the pinion in the freezer. They fell together. Driving the race in and out 10x during setup sounds like way more work. I‘ll stick to the shim under the bearing method here. Thx.

 

[67charger383]

I put the pumpkin ball in the freezer for 2 days and baked the bearing in the oven till it was 400 degrees. No machine shop needed. It dropped right on.

 

[Cranky]

400 is way hotter than it needs to be.....255-260 is max. @400 you stand to change the metallurgically and produce alterations in diameter or hardness.

 

[1 Wild R/T]

When I worked for a major bearing supplier we used & sold bearing heaters like the one shown below.... notice the temperature setting in the lower right...

 

[Cranky]

When I worked for a major bearing supplier we used & sold bearing heaters like the one shown below.... notice the temperature setting in the lower right...

View attachment 951125

We had two of those at work....small and a large with the larger one having different yokes for small and larger bearings. Uh, don't think I ever knew what the square bars were called until now. Also had an oven that was never turned off. I bought a single burner hot plate for home use....

Hey @67charger383 Let us know if that 400* bearing holds up. It will most likely be ok if it didn't turn light blue....