Checking "Run-Out"...
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
Checking "Run-Out"...
I know that it has been discussed before but I can’t seem to find the exact thread. I keep hearing form folks to “be sure the run-out” is correct when installing new rear rotors. How do you check the run-out, and what should it be? If shims are required, where do I get them?
Racer
Joined: Mar 2005
Posts: 294
Likes: 1
From: Racine Wisconsin
http://forums.corvetteforum.com/c3-t...nout-help.html
The thread above will provide the information and picture of the process.
The shims that I prefer are Brake Align P# BA801-XX. The XX is the thickness needed. There is a video on how to install. (www.brakealign.com). These are a bit expensive but available through the local GM parts distributor. My runout rig is pretty simple. It is just a dial indicator held to the spindle arm with a Vise Grip.
The thread above will provide the information and picture of the process.
The shims that I prefer are Brake Align P# BA801-XX. The XX is the thickness needed. There is a video on how to install. (www.brakealign.com). These are a bit expensive but available through the local GM parts distributor. My runout rig is pretty simple. It is just a dial indicator held to the spindle arm with a Vise Grip.
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
I know that it has been discussed before but I can’t seem to find the exact thread. I keep hearing form folks to “be sure the run-out” is correct when installing new rear rotors. How do you check the run-out, and what should it be? If shims are required, where do I get them?
the rotor to run a bit truer. They would go on the back side of the rotor between it and the axle flange. You can buy shimm stock at most older type auto parts houses. But this is not the best thing to do. You need for the rotor to be cut properly in the first place. And if the mechanic doing the cutting knows what he is doing and using a good machine will be able to cut the rotors without that wobble.
Race Director
Joined: Apr 2000
Posts: 17,650
Likes: 190
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
My rotor is fine, my hub wobbles slightly, new bearings just got a slight wobble over the years I guess. Shimming and o ringed calipers seems to have solved the problem 
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
The rotor needs to trun true to the axle flange with no wobbleing. Most say to simm the rotor to run a bit truer. They would go on the back side of the rotor between it and the axle flange. You can buy shimm stock at most older type auto parts houses. But this is not the best thing to do. You need for the rotor to be cut properly in the first place. And if the mechanic doing the cutting knows what he is doing and using a good machine will be able to cut the rotors without that wobble.
the rotor to run a bit truer. They would go on the back side of the rotor between it and the axle flange. You can buy shimm stock at most older type auto parts houses. But this is not the best thing to do. You need for the rotor to be cut properly in the first place. And if the mechanic doing the cutting knows what he is doing and using a good machine will be able to cut the rotors without that wobble.
