Thank you guys. Chevy 2500 from 2005 GVW 8600. 8 lugs. Also my mechanic said: ""It doesn't have the same rotors as the 9600 lb van...they are different.
The rotors are held on by the lug nuts.
Yes, it's best to change the pads, but pads will not cause a vibration.
I can check for rust on...