Roger L

I removed the old front rotors and installed new and found the left side ran out .010 and right side ran out .006. After reading several previous posts I learned that in production the rotors were riveted to hub and then the rotor-hub assembly was trued so run-out would be under .002. Once the original rotors are removed you are confronted with the hub flange run out which effects rotor run out. There are several solutions to true the rotors but this one that I would like to bring to everyone's attention worked perfectly for me. NAPA is selling a new product to solve the problem of rotor run-out, it is a circular shim that is sold in .003, .006 and .009 tapers. On my right rotor I measured .006 run-out near outer edge of rotor with dial indicator and also measured run out on hub flange to find low spot on flange. I then installed the .003 shim orienting the thicker section of shim on low reading area of flange, meaning it would build up the low section, installed rotor, tightened down lug nuts and rotor run out was less the .001. I repeated the process on left side using a .006 shim and by trial and error in orienting the shim on hub and trying varying rotor/stud configurations I was able to get the rotor run out to under .002. You need to measure thickness of shim to confirm thicker side, the triangular notch indicted the thinner section of shim. You can only use one shim per hub, so a stack is not permitted, as shim is approx .020 at thinnest section plus.
Attached are photos to help clarify this. It definitely worked great for me and hope this helps another member in future, Good luck.

62Jeff

Very cool idea!

Powershift

Thanks for posting. Stainless Steel Brakes had these available many years ago, but I haven't heard about them lately. Glad NAPA still has them around.

Do you have all the NAPA Part Numbers?? The one shown in your picture looks like BA 803-06. Is this correct, or are they using a different number??

Larry

new vette 62

They are expensive. The part numbers are ba80303 is for .003 ba80306 is .006 and ba80309 is for .009. I bought flat shim stock in different thickness and cut out washers to get where I needed to be. The shims from NAPA look a lot easier but a lot more expensive.

Plasticman

Plasticman

That is what I do (have a vareity of SS thin shim washers).

Here is one price listing:
Federated Drums and Rotor

Part no: BA90703
Description: HUB CORRECTION PLATE

Part No: BA90703
List Price: $51.30
Save: -27.33

Your Price: $ 27.57

Plasticman

stratplus

Great video...

Roger L

the advantage of the NAPA shim is that it is 360 degree uniform support behind the rotor as opposed to shim washers on each stud. It works and very please with results.
Roger

Scott Marzahl

Looks like an awesome shim setup, good results and pleased is always good news.

mikem350

It is a REAL PITA to make and trial fit the washers..I got brass shim stock from hobby shop...
Do tire stores still have a brake lathe machine that trues rotors on the car? That would be another alternative!!

TCracingCA

I have Coleman product rotors and hubs! Better precision!

midyearvette

precision is what it's all about
nothing wrong with machining a new rotor on an old hub to true the whole assy....be sure to mark for orientation unless you re rivet them.....
a lot better than any shim idea....jmo....

mikem350

Don't even need rivets...flat head screws work too..tap the holes...like 1/4 inch??? I think Baer sells 'em

Mike Ward

That's a far better alternative than shims. Almost as good as not changing the rotors in the first place- 99% of the time it's unnecessary.

JohnZ

Dunno about tire stores, but any decent brake shop (or a GOOD Corvette shop) should have an on-the-car rotor finisher.

Most Corvette rotors are good for 100,000+ miles with no problems when using OEM organic pads; if you use semi-metallic or "race" pads, they'll eat your rotors in fairly short order.

midyearvette

even better....