Rotor Runout Question
Thread Starter
Burning Brakes
Joined: Aug 2011
Posts: 983
Likes: 35
From: Redding California
Rotor Runout Question
Hello all and I hope everyone had a great Thanksgiving. I've heard the term "runout" for many years here and there on the forum and never paid too much attention to it. I think it's time to educate myself about this. I've searched the forum for a detailed description of what this means and how to deal with it but have been unable to find anything really in depth. If anyone could direct me to a thread that covers this topic well I'd appreciate it. I consider myself a very capable DIY'er and well versed in cars. With that said, I've never dealt with rotor runout. I have a 68 that I've been working on over the years. It has rebuilt calipers and replacement rotors sourced from one of our vendors. I just put the front rotors on the front and the rear rotors on the rear and called it good. The car has not seen the road yet. I'd really love to know what runout does to the performance of our Vettes and why it's important to check it. Furthermore, how do I check for it, fix it and what are acceptable tolerances? Thanks in advance, Jason
Drifting
Joined: Aug 2006
Posts: 1,728
Likes: 193
From: Scottsdale Arizona
I would look at the utube videos like this one
http://www.bing.com/videos/search?q=...=0&FORM=VDQVAP
http://www.bing.com/videos/search?q=...=0&FORM=VDQVAP
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,597
Likes: 7,046
From: New Or-leens Loo-z-anna
FWIW.....................If the rotor does not "sit" flat on the hub, rotor run-out exists.
If the thickness of the rotor varies where the pads press against it, the variation can also be called "run-out".
If the thickness of the rotor varies where the pads press against it, the variation can also be called "run-out".
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Here's an old thread with some info. There are now tapered shims available to correct it. Because GM mated the rotor and hub or rear spindle together and then machined the rotor, they are not necessarily true once separated. Sometimes a new rotor bolted to the old hub will wobble, or if the originals are separated and not put back the same.
https://www.corvetteforum.com/forums...post1567002304
https://www.corvetteforum.com/forums...post1567002304
Last edited by '75; Nov 26, 2016 at 09:27 PM.
