Contact Patterns on Ring Gears

[MNotary]

Bruce and Pablo, are you still here?

I am putting a Weddle 4 spider differential in a Type 1 IRS single side cover. I was wondering if those differentials will move the ring gear enough to warrant checking the wear pattern? Is backlash only set by moving the pinion? That would really change the pattern.

Type 2 and swingaxle are what I am familiar with.

[Bruce2]

Changing the diff will always affect the backlash and the contact pattern. It doesn't matter what diff you install, even changing to another stock diff will affect the backlash. You must check it.
Backlash is not set by moving the pinion, it's adjusted by moving the ring gear into or out of mesh with the pinion. In an IRS trans, the shims are between the diff bearing's outer race and the side cover/main case.

[MNotary]

I have had good luck on 002 gear boxes changing from 2 spider to a VW 4 spider differential. The pattern has always been good using what was in it. Out of 5 gearboxes, one I moved in one shim thickness, and it wouldn't have been that bad if it was going in something without a lot of abuse.

I was afraid of that on the backlash for the Type 1 IRS. Pressing the race in and out will not be fun. And not doing any Type 1 IRS, I won't have any shims to choose from. Still have to clean the main case, so maybe next week we'll check the pattern then.

Good hearing from one of the old crew.

Mike