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

[MNotary]

Some photos.. been a little side tracked.

20210729_193729[1].jpg

20210729_193628[1].jpg

[Bruce2]

Use less grease.
What does the coast side of the ring gear teeth look like?

[MNotary]

Use less grease.
What does the coast side of the ring gear teeth look like?

Type 1 Ring gear A.jpg

Type 1 ring gear.jpg

I forgot to do it. This is all I have.

[Bruce2]

When you use less grease, the contact can push the grease out of the way.

You need to try to increase the force between the gears. I install the flanges then insert a long screwdriver through one of the threaded holes and wedge the end against the casting to stop that flange from turning. Then with one hand on the other flange, I hold it to give it some resistance while turning the input shaft.

[MNotary]

I made a small piece to thread into the spider gears to lock the differential. I have someone put drag on the flanges and run the drill on the pinion. I did over grease... I know better, that is the GM marking grease... and I usually only do a few of the gears also.... now that I think about it my son may have done it when I wasn't there.. and now I just called him and that is what happened. We dragged the forward side pretty good but I forgot to do the coast. Bus transmissions are much easier. Now I have to dig up a shift fork adjustment fixture for an Type 1 IRS.

[MNotary]

IMG-20210925-WA0007.jpg

And that looks much better on the grease application. It looks like my pattern might be a bit deeper than what you have there.

On setting the shift forks, did the Crown MFG. fixture come with a spacer for the later Type 1 big bearing? I have the sleeve for the earlier bearing, but it definitely needs a spacer with the sleeve for the earlier bearing removed. Or does this fixture not work with the big bearing? Did Crown go out of business prior to the bearing change? .. or maybe quit making tools for VW?

[Bruce2]

You need to put the large nut on the pinion bearing to seat the bearing before you setup the forks.