by 01Convertible » Wed Apr 20, 2016 12:32 pm
I don't drive my convertible year-round, but more of a Sunday driver kind of thing. I noticed that shortly after having my son-in-law replace the brake pads, I started noticing a front wheel shimmy. It really got worse when driving on hot summer days. Anyhow, after putting up with this for about 8 months, I changed the brake rotors with cheap ones from AutoZone (Duralast #31260) for about $30 each. What I noticed about the old rotors were that the outside surface was flat and smooth, but the inside surfaces were irregular with a rusty outer and inner band. This left only about 1/3 of the total surface area that looked like it was making good contact.
New rotors eliminated 90% of the wheel shimmy - tire rotation and rebalance (all 4 were a little off) took care of the other 10%. I'm now shimmy-free for less than $70 (I have lifetime rotation and balance on my tires).
Now I have to work on my valve cover leak (rear bank).
UPDATE, UPDATE, UPDATE!
It turned out that my wheel shimmy returned after driving a while. When I got home I used my "non-contact" infra-red thermometer (the kind with a laser pointer in them) to read the front rotor temperatures and the caliper temps. I discovered that my right-front rotor was around 340 degrees and the caliper was around 235 degrees! The left front caliper was around 105 degrees and the rotor was only about 160 degrees. This definitely indicated that a caliper was dragging and not releasing properly after brake applications.
I replaced both calipers and their hoses today. The hoses cost about $20 each from AutoZone and I paid about $53 each for the calipers. Everything is available for less from Rockauto.com, but then you have to ship the cores back as well as wait for the parts to arrive. I paid more for convenience. Anyhow, the bottom line is that the shimmy is definitely gone and both brake rotors are now running within 20 degrees of each other.
The temperature measuring trick may be of benefit to others that are battling this wheel shimmy thing. BTW, my caliper did not seem to be sticking when I changed the rotors and pads. The piston easily pushed back into the caliper body, so there was no reason for me to believe that it was sticking. I have also heard of defective hoses that would trap hydraulic pressure and cause the caliper to drag. I changed both, so I really can't say for sure whether it was the caliper or the hose (my money would be on the caliper though). Hope this helps some of you.
2001 SLE Convertible V-6 Automatic