The Stovebolt Site Forums The Shop Area Driveline Pinion slop in a 1962 55T differential.

So, I've been driving around in my '62 C10 and I noticed a vibration coming from the drive line. I figured U-Joints, but when I crawled under the truck this morning, I found I was wrong. There is a lot of slop in the pinion. I have never taken one of these differentials apart before. I know that with the third member, these are a lot easier to work on. I won't have to pull the entire differential and axle housing to fix it, just the gear cluster. At least, that's the way I understand it. Please correct me if I'm wrong.

I still have the factory 3.90:1 non-positraction set up. I know that now would be the perfect time to upgrade to the 3.38:1 setup, but I'm on a budget and I actually like the 3.90:1.

What are the chances that I am only looking at a rear seal and probably bearings? What other small consumables am I looking at?

I'm pretty good with the mechanics ( just rebuilt the engine with no snags), but I'm not sure I have all the tools I need for this job. I could probably borrow what I don't have though. Is this something I should attempt, or pull it and take it to a shop?

There are several places slop can develop in a rear end- - - -wear of the ring and pinion gears, bearings, looseness between the axle gears and spider gears, wear of the cross pin the spider gears run on, axle spline wear, etc. There are adjustments that can minimize slack between the gears, but when they are moved, the result is almost always a whine caused by interrupting the contact pattern between the gears that has established itself for decades of running in the same relationship. Axle gears, spider gears, pivot pin, and axle spline wear all require replacement of scarce, expensive parts. The best bet is to find a complete rear end to replace the sloppy one. 50-something years ago original equipment parts might have been available, but finding new individual parts now (other than bearings) would be difficult. Put an ad into the swap meet forum- - - -somebody probably has one in better condition than yours stashed away. Setting up a rear end properly was one of the most difficult skills I tried to teach- - - -it takes a huge amount of experience to do one right.
Jerry

Jerry,

That's pretty much what I figured. That's why I've always farmed out this kind of work in the past. Let the experts do their thing. I was figuring on flushing the axle housing and install new axle bearings/seals while I had the differential out. I will probably just drop the carrier and take that to a shop. Let them give it the professional once over.

Currently, I have motion in the pinion, not really in/out, but up/down and side/side. Could be bearings are gone. I hope it's not wear in the carrier. I did see a 1955-2nd series 55T carrier on ebay when I was looking earlier.

I have worked on the later model differentials (non-3rd member) before with varying results, usually good, but I prefer to let the experts handle it.

It sounds like your pinion bearings are extremely worn. I imagine that you are hearing some loud noises. With worn pinion bearings, you can expect some abnormal wear on the ring and pinion gears.

Thanks Carl. I have been hearing some noise back there as well. I have gotten some good recommendation for local shops from local friends. I will contact them on Monday. Find out if they want me to drive it down for a cursory inspection or just pull the 3rd member and bring that down.

It's been 22 years since I needed a differential rebuilt.

Worn pinion bearings usually whine, so if that is the case, that would be where to start.

Ed

I think this video sums up the problem. It's pretty obvious.

Pinion Slop Video

Pulled the third member today. Cursory inspection shows no unusual damage. I might have caught it before it destroyed the ring and pinion. There may still be wear issues, but no bad teeth or no extra metal in the oil. Local shop is going to look at it as soon as I can get an appointment. I'm waiting to hear back from them now. I stopped in earlier, showed them the video above. When I called this afternoon after pulling the third member, they were at lunch.

Just got the call from the shop. Bearings were toast. Ring and Pinion were worn beyond serviceable tolerances. I'm dropping a set of 3.38:1 gears into it to replace the 3.90:1 gears that were in it. Too bad I have never found the ultra rare 55T posi carrier that was an option on these old trucks. Now would have been a good time to have installed it. :-(

I should have the third member back tomorrow.

I have a pile of carriers if you can wait a few days. Probably even have a 62 dated one.

The original carrier is in good shape. It's just the gears and a few bearings that are bad. While I appreciate the offer, I have already given the go-ahead to do the work. Unless you have a Posi-traction unit for a 55T rear end (not very common), It doesn't really matter. It was only a wish that I could have changed to the Posi at the same time. If I ever do find one, I will consider doing the work over again to install it. At this point, a posi is still in the realm of pipe-dream. Probably never going to happen. But I do appreciate the thought.

I have about 30 positraction carriers. That's why I replied.

And the carrier is not the same as a 3rd member. A 3rd member us the whole drop out

True. I knew the difference between the carrier and third member. I wish I had the cash to do this. Third member will be ready in the morning. So it's too late to ask the shop to wait for a new part, plus this repair was not in the budget, so I've got to hold off on any more purchases. I do appreciate it though. I may come back to you when I have a few more bucks to buy a carrier from you. Got to get a new job though. Been out of work since June. Not a lot of room in the budget for wants, just needs.

You can call me even. That posi unit is very common. About 1 in 15 chevy trucks had them in the early 60's . 509 218 4226

Buzz me. I always have them.

Truckfarm72, selling outside the Swap Meet Forums is prohibited.

Please don't censor Truckfarm for that. It's not being sold today. We will take this conversation offline.

Ok. I won't sell. Justhorsenround. Considering I have supplied a huge number of ho52 4.10 centers to members here. That's your loss. I offered a part when he was looking. That's all.

The reason selling is restricted to the swap meet area is to keep the site organized and searchable for the members. The selling of items is encouraged however offers outside of the swap meet forums should be done via email or PM. Thanks for your understanding. I'll edit the post and we'll move on.

I got the third member back this morning. Once the rain stops, I can install it. Also, I'm having touble locating wheel seals for it. I want to change those while I have the axles out. Both NAPA and O'Rielly show the seals for a '62 C10 are for an HO33 or HO35. I thought that my GM 55T was an HO52.

It is always best to get the numbers off the old seals themselves, if they are visible.

Ed

That is best. I will get out and pull them when it stops raining. I was trying to get all my parts lined up and ready. Rain is expected for the next 3-4 days out here. Brief intervals of no rain, but mostly raining. At least I can work under the truck and not get too wet, but I prefer to be dry.

I pulled the wheel seals earlier today, and I also got a National P/N from 3B. Armed with that information I was able to get the wheel seals. It took trips to 5 different part stores, but I got them.

With those parts, I was able to finish putting the rear end back together.

Man, it drives like a whole different truck now. That pinion bearing must have been going bad for a long time. The whine is gone, the vibrations are gone, and with the new 3.38:1 gears, it makes a world of difference.

Thanks for all the help and allowing me to use all y'all as a sounding board.

Hy 62Stick, no problaymo, I'm glad it all worked out.