Right Stuff Rear Disc Brakes & Buick Wheels

Granted, I didn't check this before I jumped in with both feet but now here I am, half torn down with a fitment issue.

Has anyone used the Right Stuff rear disc brake kit with stock 15x7 Buick wheels? I'm trying and my wheels rub the outboard edge of the caliper.

Here's a few pictures. I used an old nasty wheel because it shows the shiny scrub area much better.

It looks like maybe a WG wheel would move the offending area outboard 1/2 inch. Anyone have a picture of the backside of a 15x8? Spacers? Grind the caliper? Mount it and run the piss out of it and let it "clearance" itself? (just kidding on that last one!)

Oh well, maybe Santa is bringing me some 17" wheels for Christmas!

 

Had the same problem on my truck just ground the calibers till they fit.

 

I'd be reluctant to grind that area. Do you have enough stud length to use a 1/4" spacer, or will a spacer cause tire clearance issues with the fender?

 

I wouldn't grind on that area of the caliper. If ya do anything but different wheels try the spacer.To test it before getting the spacers use some flat washers to bring it out until you see how much room you will need to get clearance.

 

I'm getting some shims sent that will pull the caliper mount back toward the diff. Hopefully, that will give me some leeway. I might hit the caliper with a file just to clean up the sandy looking finish on those corners to get a few thousandths more clearance.

I'd really like to see the backside of a 15x8 to see if they are welded a lot closer to the ridge that I'm hitting.

I've been running a set of 275-60R15 on stock 15x7 Buick wheels on a 70 GS. I have never heard the 275's rub so I believe I have at least an inch in either direction for clearance. To run a spacer I'll definitely have to get some longer studs. I figure the difference between discs and drums will set the wheels out about an 1/8" but that is trivial.

 

Well, I've tried to reply to Curt McKim, the guy that makes new Buick wheels from old centers and it has rejected every message I've tried to send. Anyone got a 15x8 off the car they can take a picture of the backside? How about the backside of a WG wheel?

Thanks

 

i have 15x8(4.5bs) cragers with a 275-60 15 no issues besides the brakes dragging due to stock disc/drum porportional valve...currently have stock 14x? black steelies with a 225-70 or 75 tire on and no issues either

 

what rotors are you using?

 

me? the rotors that came with the kit, beleive theyre 79 camaro rotors
the kit came with various caliper shims to work with various applications

 

What? You managed to get a 14" wheel over these things?

The ones I have are whatever came with the kit, too!

Here's a picture of the Buick 15x7 with the caliper rubbing. This is why I want to see the back of a WG or a 15x8. If the center had less backspacing, it looks like it will clear.

 

can I get a measurment of the rotor? and height laying flat

 

I'll do that in the morning. We just got several inches of snow and I'm not feeling too peppy tonight.

Merry Christmas.

 

yes, i have 14in steelies on these ...i didnt think they would clear, but needed them to pass inspection...now i've just been driving them in the winter cause the 2 rears are winter tread
and my summer treads are garbage, mainly due to inproper inflation and bad front alignment..ooops lol

 

I don't suppose you have a picture of your rear disc setup handy do you? I'd like to do a visual comparison.

 

nope, and its fricking cold out and snow everywhere lol

 

ps, this thread is pissing me off lol
I was planning on going 15x8 buick rallys with 265-50s all around
That was the whole point in getting these instead of the big 6 and 4 piston brake setup...

 

they should be 11x 1in thick, just like the factorey fronts, but a lot more shallow due to not having the hub asembly like the fronts

 

Yes, that's close enough to what I measured. 11x.97, 2.25 from back to front.

2.25 total height minus the .97 for the rotor thickness leaves us with a measured hat height of 1.250. Do they make a similar disc with a taller hat? Another .250 would be great!

The drums are .130 at the axle/wheel surface. The discs are .290 at the axle/wheel so that adds a bit.

I have front discs and have never had a problem. I'm kind of baffled. McWheels said the wheels he makes would only work if the front discs work, which they all do. He says he can make a 15x8 wheel with as little as 4.0 backspace so that would be 1/2 more than most people use. I am guessing that would be the same backspace as a standard WG 15x7 but with another 1.250 outwards. Add to that the .160 and I'd have 1.41 inches more per side. I think that would be tight with a 275 60.

Bummer!

Pictures:

 

Any new ideas? Is having some milled out of the inside of the hat an option? It is .290" thick. Would .040" be too much, leaving a 1/4 inch?

I'm just thinking about a bit here and a touch there would add up to more clearance. File a little off the pin bosses, shim the caliper bracket a 1/16" and maybe add a spacer for the wheel. I've pretty much decided I'm going to need longer studs.

Any of this sound off limits or unsafe?

 

So I have put shims between the housing and caliper bracket and it is helping. I've also elongated the hole that mounts the caliper bracket to the housing and dropped it a bit but still have plenty of clearance between the rotor and the caliper pins.

The problem I now have is what rotors do I have and what rotors are used in the TSM kit? The TSM brackets are way more set in toward the center than the Right Stuff, which I believe would solve all of my problems. The RS kit actually is milled out around the rear flange but that just may be the difference in thickness of the two brackets. I can't say for sure without both parts in my hand.

I'm not knocking the Right Stuff kit because I believe it does work for just about every 15" wheel other than a Buick due to the commonality of the center between 14" and 15" wheels.

Anyone hazard a guess? I've PM'd GStage1 (George) to see if he can give me some guidance.