The Stovebolt Site Forums The Shop Area Engine Shop Rear diff question

I bought a '58 rear axle to hang under my '50 chassis. I have no knowledge of the past life of the '58 axle. I cleaned everything up, replaced all the seals and brake components and welded the spring perches onto the axle. It finally came time to push the chassis out of the garage. It moves about 6 inches and locked up the back wheels. It'll roll backwards fine.

I've done enough inspecting to find the problem is the pinion gear. I've tightened the main bolt on the u-joint connection as tight as I can get it, but the pinion still has about a half inch of front-to-back movement. So, as I start to roll it forward, the pinion shifts back and binds up the gear. I don't have the driveshaft in place yet.

Anyone have any idea what I'm missing or doing wrong? I've thought I may need to pull the whole third member out and reshim the main bearing, but don't know if that will solve my problem.

Sounds like a bad pinion bearing(s)

How would they be bad? Just worn out/broken? Thanks for the response.

I think you left out something, 1/2" is more than just worn.

It sounds like the front pinion bearing is missing, or it's lost all its bearing rollers. Take the pinion nut off, remove the yoke and front seal, and see if there's a bearing behind the seal. I'll bet you find no bearing at all, or only the inner and outer bearing races, no rollers!

Will the seller supply you another rear axle? I know used parts are sold "as is", but most wrecking yards will do a swap rather than a refund. (assuming you got it at a dismantler)
Jerry

Thanks for the info. I'll pull the seal and see what's behind there. I bought it from a private seller, so whatever I find will have to be fixed or replaced by me. No big deal though. I knew I was buying a 50 year old part and it may need some work.

Okay. I finally made time to open up the front of the rear diff. I pulled off, in this order, the pinion nut, washer, u-joint connection, seal, and pinion bearing. The bearing looks to be in good condition.

With the bearing pushed as far up the pinion shaft as it will go, I can still move the pinion into the housing by a 1/4 to 1/2 inch.

Any ideas what might be missing? What's my next step? Do I need to remove the axles and pull the whole 3rd member out? I can post pictures if that will help with troubleshooting. Thanks for the help.

Can you see any rollers in the inside pinion bearing? As mentioned before they may be gone, sounds like a good theory to me too.

Grigg

Shims? Seems a bit too much travel for shims, but as you said, you don't know what's been done to it.

Must be something wrong with the rear brg. Could someone have put new brgs. in & never compressed the crush sleeve?

Thanks for the feedback. The rollers on the pinion bearing are in perfect condition.

Without anything obviously missing/wrong, it looks like I'm going to have to remove the whole 3rd member and start from scratch.

Bendan M, I love the quote on your signature. I feel that way every time I walk into the garage. :-)

RedGreen,

If its not repairable, I have an idea for you. Have a good pumpkin here, 3.90 ratio, came out of my 58 with 110,000 miles. Good shape, no problems, but I replaced it with a pumpkin with a 3.38 already in place. Its in my garage, and free for the asking. You are in the general neighborhood (kinda), so come on by and pick it up if you wish.