8 3/4 489 case pinion bearings

[billytuffnuts]

I've been told when swapping gears its a good idea to replace the pinion bearing since it has to be pressed off. I'm just a little confused if I only need to replace the inner or outer or both?

I believe I have a 10 spline pinion shaft as the pinion nut was 1 1/8" as mentioned in another thread on here. Does anybody know what the diameter of that is? The bearings seem to be listed by shaft diameter.

Thanks

 

[fishy68]

As long as it's pressed off correctly and the bearing is good there's no need to replace it IMO. I've reused them with no problems. The bearings are specified by case so you order them for a 489 case. They were used starting in 1970. Here's a chart showing the bearings and part numbers for 8-3/4 rears.

8 3/4" 3rd member bearings.

741 case
Differential 57-early 69: 25590/25520
Differential Late 69-74: LM104949/LM104912
Pinion inner: HM89446/HM89410
Pinion outer:M88048/M88010
Seal: 8515N

742 case
Differential : 25590/25520
Pinion inner: HM803149/HM803110
Pinion outer: HM89443/HM89410
Seal: 7216

489 case
Differential: LM104949/LM104912
Pinion inner: M804049/M804010
Pinion outer: M88048/M88010
Seal: 5126

You should be able to take these numbers to most any parts store and get them.

 

[billytuffnuts]

thanks!

 

[fishy68]

Your welcome

 

[STRorange]

Nice list of Bearings there Fishy68!

Loving the 'any parts store' quote, here in the UK ''if it ain't metric, don't ask'' lol...
Best wishes from the UK