costpenn

I am having to change out both rear wheel bearings on my completely rebuilt 72 442 convert because of the issue with the replacement taper cone (A9) bearing sold for this application by all the major manufacturers/resellers.

Here's a link to the thread I did on the rebuilding/resto of this unit last year:
https://classicoldsmobile.com/forums...d-product.html

I have only 10 miles on the car, and some horrible noises started coming from the rear end. Jacked it up and the left wheel had close to 1/2 inch of play inboard and outboard, and 1/4 inch up and down. I took it to a shop I trusted here in Dallas, and they told me the axle tube where the bearing sits in is completely wallowed out and I need to get a whole new rear end. I started dreading the work that would be involved, so I brought it home and thought I'd check it myself one last time before starting to get a replacement unit, remove the old one etc...

Well, that was NOT the problem. When I removed the axle, I noticed that the cone wasnt riding in the race, almost as if it was the wrong bearing width. I then vaguely remembered something I had read here a long time ago about being careful on rear axle bearing designs. Sure enough, I found this thread https://classicoldsmobile.com/forums...seal-help.html that spoke about this problem.

The issue is that I happen to have one of those somewhat rare 71-72 rear axles where the "pocket" the wheel bearing sits in was bored deeper than normal. OLDS507 and others lay out the problem, which is easily solved by using the original barrel style one piece wheel bearing. They're available out there on evilbay. Dont take a chance on yours!!!

monzaz

??? You might have had the wrong SEAL thickness not the wrong bearing.

there is the 2146 seal (.465) AND THE 712146 SEAL (.490)

that WILL CAUSE THE Tapered bearing to fall from its race and have a ton of end play and could cause a catastrophe if left unchecked.

I think for drag racing the barrel type bearing of OLD GM supplied parts was a better choice. But the tapered bearing will be better for all around driving performance as long as the install is correct with the correct seal thickness. Jim

JD

Sampson

First off Cost Penn your rear end resto looked great. I know you had to be sick to run into problems at 10 miles. Second thanks for posting the problem. Your timing could not have been better. I just ordered all parts to convert my SA o. Rear to 3:42 posi today. I will be sure to look at potential problems thanks to you.

Allan R

Joe, I'm so sorry to hear what happened. I went through this last year when I built my rear also. I pulled the axles and found one side with conical bearings and the other with the OEM barrell. Was going to install conical/races but ended up doing it the GM way.
The bad news day followed by New barrel bearings ready to go

BTW, in reviewing your axle build? I notice that you went all out with the markings and decals, but forgot to install the washers that would have held the drums on while it was being positioned for installation to the car. How's that for picky??

costpenn

Allan, I'm very surprised at you. It's so obvious my car came with the super rare W38 option - Rear Drum Washer/Retainer Delete.

Allan R

Ahhh, now I see. Along with bypass code Y94 - Methane Production at Source.

I on the other hand also have the uber strato rarest of rare V36 - Drum - Rear with Heat Resistant Coating, and Z27 - Rear Axle - Aluminum Differential Finish c/w Aluminum Cover

Run to Rund

Even if the end was wallowed out, new ends could be welded on, so long as a jig, etc. is used so they are dead straight.

costpenn

I had read it is absolutely critical to get it dead straight. Dont know if I could trust anyone around here to make sure that happened!!

costpenn

Hey! I thought Z27 was only available on Black 72's if you ordered the HD cigarette lighter!