Virgin housing setup questions, 8 3/4

[jos51700]

I finally found a NOS aluminum carrier for my 8 3/4. When setting up a ring and pinion for a brand new 742 setup, there's no spacer to start with. How is this spacer chosen for an unknown setup (I don't even have an old housing sitting around.).

Also, I'm going to run a Eaton Tru-Trac. I'm seeing some references to 33 spline, and 30 spline axles in the literature. I have aftermarket axles in my current housing and I was just going to reuse them. Is there really two different spline counts?

 

[Kendog 170]

I read on here that on your pinion gear there is a spec to get started with and then shim from there. Some people hone the inside of the pinion bearing so you can tap on and off by hand for shimming or buy a cheap Rock auto bearing to hone and get shimming right before pressing on your good bearing. Wait for more responses. I figured if I posted it would get the ball rolling with responses.
Can't help you with spline count. IDK

 

[john-9]

with no shim available on 741 and 742 cases start with a 0.090 shim for the initial set up and adjust your shim thickness based on the gear pattern you get ,, 489 cases start with a 0.030 shim ,, make you shim selections in moves of 0.003 to see any change in the gear pattern. you should have 30 spline axles unless someone had a 35 spline spool only set up

 

[Bobzilla]

Some people hone the inside of the pinion bearing so you can tap on and off by hand for shimming or buy a cheap Rock auto bearing to hone and get shimming right before pressing on your good bearing.

I agree. I did this and it was much easier than I thought. I just used a cheap grinding stone on a die grinder and kept it moving. Did not take very long at all. Just be sure to wash the bearing before any use to get the grit out. Mine is now a snug slip fit so it can go on and come off easily.

 

[Oldmanmopar]

I Only ever had one aluminum carrier. I would never put one in again. Great for road course not the best for drag racing. It is the housing flex that cause cap breakage that destroys the gear set.

The axles crack the caps from stress of the axles moving with the axle tubes. The outside of the axles move forward causing the splines to **** rearward that cracks the caps. Brace the housing. All I run is a 742. If they were strong enough for the Max Wedge and race Hemi they are good for me.

 

[jos51700]

I Only ever had one aluminum carrier. I would never put one in again. Great for road course not the best for drag racing. It is the housing flex that cause cap breakage that destroys the gear set.

The axles crack the caps from stress of the axles moving with the axle tubes. The outside of the axles move forward causing the splines to **** rearward that cracks the caps. Brace the housing. All I run is a 742. If they were strong enough for the Max Wedge and race Hemi they are good for me.

I hadn't considered that until now. This is only a street car, and I won't ever put slicks or anything on it, but the way you explained that makes perfect sense.