Pinion bearing

[SCD]

Hi:
One quick question about driveline vibration. I have read all the post about vibrations and think I have it narrowed to tail shaft bushing or pinion bearing. The question I have, can you feel the roughness of a pinion bearing by turning the pinion shaft.
I removed the driveshaft and tires and breakdrums and turned the pinion shaft by hand and it felt fine. Is it possible that there are a couple of nick on some of the tapered rollers that I can't feel when turning it by hand?
Thanks
Steve

 

[Nick Micale]

Never seen a bad pinion bearing, but anything is possible?

The axles and axle bearings on the other hand are very common wear items in a GN rear end, and will cause the problem you experience.

 

[SCD]

Update on vibration hunting.

I put the gn up on my lift and ran the drive train and listened to the differential with a rake handle. I listened to all the bearings. Pinion, axle, and differential carrier bearings. There was no noticeable sound difference.
There was a slight vibration at the torqe converter so I moved it 1/3 turn and road tested the car.
The vibration in my front floor was gone but the rear vibration was still there.

This morning I started to tear the rear down, removed axles,(axle bearings looked fine). Removed carrier and found it!! Right carrier bearing and race pitted. Then I pulled the pinion shaft, those bearings were good also.

My question is should I replace the one bad bearing or replace them all. If I replace them all do I have to get this rear shimmed again? There is 60,000 miles on the car and ring and pinion gears look good.

Any input will be appreciated.

Steve

 

[challengermike]

If you are in there i would do all the bearings.As for the shims most of the time you will not have to change the shims.Even when i setup a diff with new gears 85% of the time the stock shims put it right where it needs to be.

 

[SCD]

Mike thanks for info ,replacing bearings tomarrow.
20- 25 in. lbs on pinion bearing pre load right?
should I use 80-90 plain gear oil with additive or synthic with out?

Thanks again

Steve