Rear differential bearings
 

Ok I was pestering about lowering my 66 c10 and endlessly debating if I should buy a chassis from a 71 for a 5 lug conversion. Long story short I bought the chassis and just got done tearing the rear apart. Kind of disappointed in its condition but I suppose it could be worse. The only major issue is the passenger side backing plate is wasted and the outer bearing fell apart. I've replaced axle seals before but never any bearings. I did get the race in the tube out with a slide hammer but I think the ring gear and carrier should at least come out for a thorough cleaning. I know those main caps need a very specific torque but beyond that I'm looking for any advice so I dont end up destroying the whole thing. Thanks

Re: Rear differential bearings
 

Just keep each shim on its correct side, and you should be good.

Re: Rear differential bearings
 

See I didn't even know there would be shims in there. Thank you

Re: Rear differential bearings
 

Did you use the 71 rear or just the 5 lug axles? I am starting to look for a set of 6 lug, 30 spline, 30.5 inch axles. I want to keep my 63 housing, but I can't get a posi for 17 lug axles.

Re: Rear differential bearings
 

I'm using the whole rear end, maybe. I say maybe because things arent going as planned lol as I'll elaborate in another message in this thread

Re: Rear differential bearings
 

Well what I was foolishly hoping was just going to be a fluid change and axle seals has ballooned lol. After the teardown I knew the seals were bad so consequently the outer bearings needed changing as well. Being that far into it I took the carrier out because I may as well change those bearings as well. In doing so I noticed the pinion bearings were crunchy so I removed it. Having the carrier out I was better able to inspect things and noticed the teeth not submerged in gear oil are slightly pitted. It's going to be an occasional driver so I dont know how the pitted ring gear will affect longevity and what do I need to know installing new pinion bearings? Like I said earlier, I've never been this far into a total diff rebuild

I'm wondering when I should cut my losses and start looking for another rear end which may or may not be in better shape. :o

Re: Rear differential bearings
 

You're really going to want a press and a bearing splitter to change the bearings, or you can take the parts to a shop and have them pop the old ones and install the new ones.

Ideally you should re-check everything (bearing pre-load, tooth patterns) as you put it all together, but you can often get away with just putting it back together the same, and not over-torquing the pinion nut like a monster. There is a sleeve in-between the front and rear pinion bearings (looks like a deformed section of tube) that sets the pinion pre-load - DON'T distort it more by over-tightening.

If you have no money, you can do this. But sometimes "pay the man" is a good thing with ring & pinions.

If you don't have a limited slip in there, considering buying one now - this is a good time to put one in.

Post a pic of the pitting. You can actually get away with quite a bit of nasty.

Re: Rear differential bearings
 

I have the bearing puller and press covered. I'm glad to hear it's possible to reassemble it as it was. I do remember a video of a rebuild where a guy reused the old crush sleeve by slowing tightening the pinion nut and rolling the diff so you could hear the sleeve sliding between the bearings. As soon as the audible clink stops you have it where it was and can stop tightening. I believe the preload was ok because there is no uneven mesh problem or wear marks. I spent a couple years at a job rebuilding pumps and blowers and was fairly good at spotting sharp or unevenly worn teeth. I'll be quite relieved if this pitting is deemed useable for an occasional driver

Re: Rear differential bearings
 

I am heading to Carlisle tomorrow and will be shopping for axles. If you do get this one together and you use the entire rear, let me know if you may want to move your original 66 rear. I am not too far from Hersey and may be interested. Good luck with the one you have.
Rob

Re: Rear differential bearings
 

In my opinion, those gears are too far pitted; I'd expect them to be noisy. I hope others here will chime in too.

Do you know if it made noise before you took it apart?

Re: Rear differential bearings
 

I just bought a rolling chassis for this rear end and power steering box. This thing had to be parked for a long time for this pitting to get this bad. Even if I didnt want to cut my losses I dont know if I'm skilled enough to set up a new ring and pinion :whine:

Re: Rear differential bearings
 

Those gear teeth are far beyond useable, but for an occasional driver just doing a weekend cruise once in a while and driving it like granny, it'll probably work.

Re: Rear differential bearings
 

Yea many moons ago when I was a dumb cheapo teen mostly because I didn't have two dimes to rub together I would have absolutely reused these gears and every once in a while I hear him trying to convince me to go the cheap route so I knew these gears were toast. So in the near future after i decide to buy new everything I'll be looking for tips on setting preload and centering up the carrier. Thanks everyone

Re: Rear differential bearings
 

Was the 6 lug ring and pinion bad as well? If you aren't planning on changing the gear ratio as well, just use the carrier and R&P from the 66 axle in the 71 housing

Re: Rear differential bearings
 

The 66 is geared at 3.73 and I was hoping to go to a higher ratio with this change to 3.40 or 3.08. The 71 is geared at 3.08 but rebuilding it has me a bit worried

Re: Rear differential bearings
 

Ahh, I see. I bet you could source a good set of used 3.08s from someone switching to 3.73s. Maybe someone would want to trade your 3.73s and carrier for 3.08s

Re: Rear differential bearings
 

After copious gobs of deliberation I've decided to rebuild the toasted rear. I scanned the interwebs looking for a rebuilding guide either in written form or instructional video and after wading through a lot of videos of people with good intentions but lacking the ability to instill trust in me that they were doing things correctly. Finally I found a 2 hour long video of a gentleman from a technical school demonstrating how to rebuild a gm 10 bolt differential. Yes I know I'm rebuilding a 12 bolt but the concept and processes are the same and I'm confident now that I can get this done. I'll provide the link below for anyone interested in a fine demonstration. My next step is getting parts ordered from summit and finding a decent set of backing plates.

https://youtu.be/AsiRYnWcCQg

Re: Rear differential bearings
 

What did the axles look like where the bearings ride? Were they pitted or worn? You had said the rear had one bad bearing.
Jimmy

Re: Rear differential bearings
 

Axles are fine. I wouldn't have decided to rebuild if they were bad

Re: Rear differential bearings
 

I recently rebuilt the rear diff in my 66. It's not an easy job but just take your time. I bought a new Eaton tru-track, Richmond Gear ring & pinion. and the kit that has all of the shims, bearings. crush sleeve, and all parts needed to complete the job from Summit. I found a video on YouTube made by the Haggerty company that was very thorough. Good luck, it will be well worth your time now rather than having to do it all over again later.

Re: Rear differential bearings
 

Thank you. It's all back together and I'm fairly pleased with the results. I got good preload on the pinion and carrier bearings with about. 006 backlash but the wear pattern wasn't perfect. Its centered perfect between the peak and valleys but is a bit off center to the heel or outside of the ring gear. I know center is ideal or offset to the toe or inside of the ring but I dont know if I want to get another pinion seal and large bearing because I'm afraid I'd destroy it getting it off to get another shim under it. I saw a great rebuild video on YouTube as well from a technical school instructor and he didn't cover how many thousandths would move the pattern