I'm running into issues trying to shim out the PBR caliper carriers. Got the shim kit from Andy Z28, and using FynBye (Ed) backing plates. Got a thick and thin shim on the passenger side and the carrier still rubs. Have a thick on the driver side, same result. I have no reason to think that just adding the thin shim will resolve the problem on the driver side either. Do I need more shims? Are the carriers bent; warped? What if I filed down the carrier?

I know reading James C's thread on the subject of the disc to disc swap, he only needed one shim out of the four. Did I miss something? Do I need Andy's backing plates to make the shims work?

Trying to button up the car so I can get it back on the road.

 

Shim between the backing plates and the carriers. When you've got the correct shim size figured out, put a shim that thickness between the backing plate and axle flange. At least that's what I'd try...

 

Not a bad idea actually. I was thinking of putting washers between the carrier and the backing plate to see if I could get that centered. I'm not sure I'd ever run the car like that though. Other than Andy, is there anywhere else I could get shims for the rear ends? I am running on the idea the rotor needs to be centered on the carrier. If so, it'd be quite a bit of shimming. I think I may be looking at at least an 1/8th of an inch if not more.

I've been digging around on the backing plates, nearly all of them have washers or a spacer welded onto the mounting holes for the caliper carrier. Mine does not have that. Entirely possible that may be what I'll have to do.

 

I didn't even know there were shims available, at the time I did mine... I just used washers. Didn't take a whole lot on mine, seems like it was maybe 1/116" or so, and only on one side, but it's been A LONG TIME so my memory may have failed. (and it might even be wrong in this particular case, besides) Can't see what difference they would make, given that the contact area of the caliper carrier to the plate is only about the size of a washer anyway.

Yes I would think that ideally the rotor should be somewhat centered in the caliper carrier. Or at least, it should have plenty of clearance at each extreme of the axle end play.

Might not even be a bad idea to replace the C-clips in the rear just to keep the axles as tight as practical.

 

Good idea on the C clips, car has 172K on it, rear end was done at like 90K. I'll take it under consideration. As for the washers as a spacer, your experience has me feeling more comfortable with it, as does seeing all these plates with basically washers welded on. I'll get some washers and give it a go. The shims I got from Andy did work but nowhere near the needed clearance. I agree on the washer size being what is needed, just need to see if I need one or two washers per hole.

 

If you look, all of the aftermarket brake manufacturers or vendors, whatever, offer shims that are intended to go between the carriers and the mounting plates. You can get them from Summit, or get fancy and just order shim washers from someplace like McMaster Carr.

What GM did was use a shim between the housing and the backing plate. There are plenty of reasons to do this, such as making one less thing a service tech can foul up during a brake service. But in the real world it's not very practical to custom make shims to fit all the different axle housings in the world. Not when you can have shim washers that come in all kinds of sizes.

If this link doesn't work, just go to the home page, click shims, click on shims again, and feast your eyes on the possibilities.
https://www.mcmaster.com/#standard-shims/=1a6tskq

 

If I recall correctly I went to Lowe's and got stainless ones (they have a MUCH better collection of stainless than the other stores it seems like), they're real thin and therefore easy to set up to just the right thickness. Plus, they're stainless... never a bad thing, it seems like.