Why is it that so many aftermarket axles do not work with the factory disc setup?

The year breakdowns dont often make much sense, so I'm pretty confused about the cause.

I have a hard time imagining it's worth their trouble to create the brackets for the 82-88 delco-moraine setup, but what about the 89-92 discs? The calipers appear to be exactly the same as the 93-97 disc brakes, however the mounting brackets are different and the cooling fins were removed (likely for wheel clearance with 16" wheels after moving the hub farther towards the outside of the car).

Is there anyone out there that can shed some light on this?

 

Do you mean complete rear end assemblies or axle shafts?

 

Complete assemblies. I hate differential terminology.

 

Main thing is, the small hole in the center of the backing plate, which in turn is small because of the teeny tiny 10-bolt sized axle bearings.

 

There are many after market rear end assemblies that will accept the brakes that you want. You just have to know how to order it. If you want a Moser then order it with the 7900FM housing ends and tell them what brakes you are using so they can cut the axle flange to fit the rotors.

 

This is making a little more sense now... To be clear, I already have a set of 89-92 PBR's on my 9-bolt and this is an attempt to understand how I can upgrade my axle without resorting to getting rid of a perfectly good brake system that works with all OEM parts.

I know the 9bolt and 10bolt backing plates are different. Not sure how much that matters, but I imagine the ends on the axle would need to match my backing plates. Or are there other backing plates available affordably aftermarket that will solve that problem? I guess I coudl always source 10-bolt PBR backing plates, but such things are not often separated from the brakes themselves... big gear head, are you saying with the "7900FM" will allow me to use specifically a 10bolt PBR backing plate?

 

Both 9- and 10- bolt backing plates are available from Ed Miller:

http://www.flynbye.com/catalog/c1_p1.html

The bolt pattern is different between 9- and 10- bolt as seen below.

JamesC

 

For the PBRs, the backing plate being really simple, wouldn't be too hard to make a plate with a big enough hole in the center to fit over the larger axle bearing bores required to hold heavier-duty axle bearings than the R1563TAV, and some bolt holes to fit whatever flange the housing mfr can put on it. Might even be possible to take some stock ones and laser out the holes.

 

The 7900FM housing ends work with 10 bolt caliper brackets. I don't think Moser has housing ends for the 9 bolt brackets.

 

Thought about this & John looked into it, too: https://www.thirdgen.org/forums/brak...ml#post5374960

He did make a 9bolt bracket for CTSV, but he had 19" wheels, too - search.

I figured that the cones would be a wear item in the 9bolt w/LS2- I didn't want to learn/educate myself to become a shim expert, and parts increasingly difficult.

Dana44 was next option, but couldn't find one within my time frame.

Went with MW 12bolt with Truetrac and Wilwood D52 w/e-brake. TA cars don't need tremendous rear brakes - keep that in mind. That's also why I didn't go fixed caliper.

I don't think there are any easy answers. Good Luck!

 

All that rigamarole is exactly why I want to just bolt up my PBR's I already have and call it good.

Looks like getting the 10 bolt ends put on it and getting plates made for that is the answer.