I want to set up a 3.90 and a 4.22 starion rear.
This 4.62 pinion has the #382 on it. Dial gauge indicates 1.900 from bearing center line to pinion. Plan is to measure the used 3.90 set before i disassemble it and than get the same measurement in the starion housing and than set backlash and check pattern.

The problem is the 4.22 gear set is new and i don't have the luxury of using the dial gauge reading as a starting point. Can the correct dial gauge reading be calculated from the # i hope to find on the 4.22 pinion? The 4.22 starion rear is already assembled by a previous owner but has never been run. The preloaded are that tight we can barely turn it. I will check the pattern before i proceed.

Do the pinion bearings interchange between the the 4 cylinder truck and 88/89 starion rears?

Any pointers from those who have do the swap. I assembled Mack truck rears years ago so i do have some experience with gear set up.

Thanks

Eddie? Curtis?

The number etched on the pinion will be the variation from standard height.
Refer to the gear you are removing to get the variation in setup height.
From the early 80s Mitsu reduced dependency on the pinion markings though and just uses gauge blocks to select the pinion shim.
This procedure leads one to use the shims that came with the original housing to set height. This has been working well with the setups I have been doing.

With that tight 4.22, I would drop the ring gear out and investigate if it is the pinion preload that is tight. Might be that the seal is dry? It might be the diff preload that is tight.

You will love the short gears in a Starion, I run 4.22 at some roadcourse events and 4.62 at AutoX and hillclimbs.

While you are in there check the stack in the diff clutches. Many of them come ABBA, if you swap the inner and outers to ABAB you get a stronger lockup.

Correct of course.

In my experience, the shims are used to rule out (mostly)housing differences, and not gear differences. I always start with the old shim measurements as a reference for pinion depth.

Any one know what the standard 4.22 pinion shim thickness is?
The shim kit ranges from .055 to .065 with one .012 shim.
The 4.22 pinion on the right seems to have way more shims than the 3.54 on the left. I believe the pattern is telling me the 4.22 pinion is to close to the ring gear center line.
We ordered a shim kit for a starion rear.

Pics of the pattern.

I am no expert but from all my webwheeling experience that looks a little low. Shallow? On the ringgear? Am I correct?

Whats the backlash with this pattern?

IF the backlash is close, you May need to move the ring gear away from the pinion, and increase backlash. But you Prob just need move the pinion out some.(away from the ring gear) so you'd remove pinion shim.

I'd pull a tiny bit out of the pinion, and see if that moves the pattern up , and out some. (I bet it will)

.010-.012 it was difficult to measure due to the side bearing preload being very tight due to a to small diameters side shim rubbing on a side bearing. I could re pattern with the side shims installed correctly. I have a new shim kit.

One bearing cap was on backwards.

This shim was not seated.