A100 Rear differential.

Good morning group. It has been along time since i posted on the sight, but have been lurking in the background. 
My question is for all off the rear differential gurus in the group. 
My 67 A100 has a stock rear diff. it was removed, checked and reinstalled about 4 years ago. After the work was done i felt a vibration, not steady but a cycling vibe coming from the rear. 
It increases and decreases with the speed.  I checked the u joints to make sure they were installed correctly, they were. Took the rig to a local well known trans and diff shop. And had the owner road test it. He felt the vibe but said it seemed ok. So after working on other vehicles for a while I wanted to get back on the van. Had it out for a nice long drive last weekend and the vibe is there and maybe worse. So maybe going to have to pull it and check everything again. Im still confused about the role of the crush sleeve and how it is supposed to be installed, and what kind of axle bearings are available that dont have to have the adjustment done at the backing plate. 
Thanks in advance.

I am not a differential expert or have the tools that is why I have always taken mine into a shop to get rebuilt.

If you can or feel like making the drive to the Sacramento area I highly recommend West Coast Differentials in Rancho Cordova. I have been going there for over 20 years and they do excellent work.

Keith

Im still confused about the role of the crush sleeve and how it is supposed to be installed

There is a front and rear tapered bearing on the pinion. There must be a clearance between these two tapered surfaces for proper bearing operation. Think the front hub bearings and how you need to set preload there. The pinion depth is set using shims behind the rear bearing, then the crush sleeve is used instead of spacers or shims between the rear bearing and the front bearing to set the distance between them. This is NOT done on the hub, because the forces are around the bearing instead of pulling or pushing straight through. Also, the pinion nut must be torqued to a MUCH higher torque which would lock up the bearings if it was the means to set preload. Other designs use spacers and shims. The crush sleeve is a cheaper. quicker setup. A GOOD diff specialist can replace the crush sleeve with a spacer, but it's going to cost money to have it set up properly.

what kind of axle bearings are available that dont have to have the adjustment done at the backing plate.

The backing plate adjustment is also setting preload on tapered bearings, one at each end with a spacer block between the inner axle ends. It is a superior design compared to ball bearings or needle bearings (no side thrust) and is not riding directly on the axle like some other designs. If you MUST replace these, there are kits to do this. On a van with fairly narrow wheels and tires, they will last a good while. If you run wide sticky tires and autocross your van, they will last a much shorter time than the original bearings.
EXAMPLE the Hotchkiss TA Challenger and Roadrunner they take to various events needed 4 wheel disc brakes for the extremes they are subjected. These require no lateral movement at the disc, which forced them to use the roller bearings. They replace the bearings more than once a year.

One source
https://www.quickperformance.com/Chrysler-875-Sealed-Axle-Bearing-MO-400_p_21468.html

If you want to pinpoint the source of the vibration, there are many different things to check. One of the easiest and cheapest is to get an infrared thermometer. They sell at HF for under 50 bucks. They can be used to measure the temp of lots of different things, so it is not a one-time tool. Run the van a while at a speed that has the vibration. Pull over and check the temp at the u-joints, front pinion, carrier bearings and axle bearings. If anything is hotter than it's counterpart, that is the likely source of the vibration. This can also be used to check brake temps, engine and trans temps, even food temps in the home.

..and I'm back to lurking

Thanks for all of the great info and pictures. Will be be taking the van to my Transmission and differential shop for a proper set up.