Anyone have experience machining a GM 8.5 corporate ring gear spacer to fit an O type 673 carrier? Want to put a Richmond 3.42 on it.
I've seen posts indicating it can be done.
Sounds like the ID of the spacer needs to be increased and bolt holes need 3/8 -> 7/16? Or do bolt holes not line up at all?
This is a temp solution while wating for the aftermarket type "O" compatible posi carriers to be available again. Could be a long wait.
Best Regards,
Eric

 

Talk to @monzaz. He is the expert and a great guy.

 

Agreed. I think he was the one who originally posted about the modifications to the ring gear spacer.

 

Thanks - working with Jim now.

 

FYI - wanted to thank this forum for the good info. Kept me from getting too far in the woods trying to set up 3.42 gears on a 2-series carrier. Although I must admit to spending and hour or so wondering why my ring gear lash was .5" instead of .009".
For some reason this 70 442 convertible had a 2.78 posi installed. The build sheet says it was "SE" which is 3.23 open.
I guess the previous owner wanted better traction in the upstate NY snow and better gas mileage.

 

Swapping rear axles for better mileage was common in the late 70s during the gas crises. So was swapping to a 2bbl.

 

I found a 278 limited under an F85 68 more door in a boneyard in the late 90s. I put it in my 308 peg leg using a National Drive Train or was it Drive Train Direct off the shelf O type spacer.

The guy on the other end of the phone wanted to sell me an 8.2 spacer and I had to direct him to look harder and he found it...1998ish soooo...Spacer or the vendor(s) may not exist now???

.Use ARP bolts and washers at the corrected length to make up for the extra space. Make sure you get full-depth thread engagement. Lap the spacer to the carrier. Use Blue Loctite on clean threads and torque it. While you are in there MAW do it all the way out to the axle end bearings.

Monzaz knows all of this better than me just spewing my experience for others.

 

Drolds, thanks for the info. Question - "Lap the spacer to the carrier" sounds important but I'm not familiar. You mean like lapping valves and seats?

 

Think I understand lapping the spacer now. Get a cleaner mating surface to help prevent torque shear. I saw some posts about shearing off bolts when spacers are used, especially on hi-perf builds. Sounds logical.

 

Correct sir.