[poncho-mike]

I've got a 78 GMC Suburban that I'm having some rear end noises. The truck is a 3/4 ton 454 model with the 11,000 GVW Trailer towing package. It has a 14-bolt rear end with full floating axles.

I think the pinion bearing is going bad. The Suburban started making some noise maybe six months ago, but it wasn't very loud. Then more recently, there was an occasional light screech, sounding like perhaps a something with a sharp edge rubbingthe driveshaft.

I disconnected the driveshaft and spun the rear wheels. I noted it took more effort to turn the wheels in one direction versus the other. The truck has seeped rear axle grease at the front input for probably the last 20K miles.

Just this weekend, the noise has changed. The noise now is more of a roar, sounding like similar to brake shoes with no liner rubbing on the hubs. The rear linings have less than 10K on new brakes.

Does anyone know how hard it is to replace the front pinion bearing in an older 14-bolt rear? There is a ring of bolts around the casting the pinion shaft is mounted to.

If anybody has any thoughts, please let me know. This old truck has been a great truck for many years, but I'm having doubts about whether I want to spend any more money on it. It's not rusty, but the paint is pretty tired and it still has 250K miles on the original motor.

Thanks for any advice you have.

Mike

[RH152]

also check the hanger bearing if truck has two piece driveshaft the pinion support is is removable from front after you romove you weill need a good impact gun or a long breaker bar to loosen it and a press for the bearings if noy sure take too a proffessional shop i do these rears all the time hope this info helped

[poncho-mike]

Hi,

Thanks for the input. It has a 2-piece driveshaft and I know the driveshaft is good. I replaced driveshaft and all U-joints a couple of years ago. I am pretty sure this noise is coming from the rear.

So you can take the pinion shaft and bearings out by removing the piece on the front end of the pumpkin?

Typically how expensive is it to repair a bag pinion gear?

Mike

[Formulabruce]

yes you can,the crush is set on that part, out of rear I believe (bench)(been a while) check the ring gear while your there, I suspect that the parts will be 60 dollars, IF you dont need a pinion. if its 2wd drive its 4.11, if 4wd its probably 4.10 if the corporate 14 bolt.
I used to put posi's in these, thats how I found out a few things
RH152 has a valid point, the hangar for the 2 part shaft, when worn can cause your problem, Im not saying its not the rear, Im saying it could happen again if the middle carrier bearing is worn, but not total junk yet. Causes lots of driveshaft wobble at yoke on rear