I'm going to detail this as best as possible for the most accurate diagnosis:
Earlier this year in May, I decided to replace all 4 brake pads and rotors. I upgraded to Centric Slotted Rotors (good quality/good business) and Hawk HPS brake pads. I did the entire job myself over a few hours and drove around to bed the pads. I also bought 4 brand new tires and had a balance done at Discount Tire because my tread was very low. Afterward, on the highway, I quickly noticed a pretty bad shimmy at 50+ MPH. It was obviously something to do with the new rotors. I brought it to Honda and had them diagnose it. Turned out that I hadn't seated the new rotors on the hub correctly on the front passenger side. They scraped up any rust/dirt and reinstalled. My car was great from May until the end of November.
I had only driven about 4300 miles between May and Nov. Driving around one day, my brake pedal seemed to be VERY sensitive- I would barely put my foot on it and would have a solid grab. Once I got home and pulled into the garage, it smelled like burning and I could feel a lot of heat coming from the front. I walked around and looked and noticed that both my front rims were very hot to the touch- the front passenger more than the other and the smell was worse on that side. I figured it was a seizing caliper/piston. I brought to Honda, they diagnosed it as such and replaced the entire caliper on that side. I also had them do a full tune-up since it was there and it's due at 90k miles.
Over the last 10 days since I got the car back, I noticed that I have an intermittent wheel shimmy (like before, except this is intermittent- it's not constant like the problem mentioned above). I called Honda and the guy said "Oh, we rotated the tires when we did the job, so you probably just need a wheel balance." The next day I went to Discount Tire and had them balance all 4. Keep in mind this is after only 4500 miles on the tires (they require/recommend rotation every 6000 miles).
Driving around I still have an intermittent shimmy. It doesn't pull either way and it comes and goes. I'll be driving at 65-70 and it will start shaking pretty bad, then within a few seconds (at the same speed, same road, no difference in pavement) it fades away and stops. Then after another 15-20 seconds, it returns. It keeps doing this regardless of what road I'm on or pavement type. I cannot notice it at all until I hit 60mph.
I have had the rims checked for bends and they're fine.
The only thing simple that I can think of that I haven't done is get an alignment. It doesn't pull and hasn't been wearing uneven though, plus the problem started RIGHT after I brought it to Honda for the seizing caliper. I'm very weary to bring it back to Honda again because I've had this car 3 years now, done all the maintenance myself to this point and haven't had a problem until I started bringing it there. At the same time, I feel like it's their problem to fix since they introduced it the last time they worked on my car.
Any idea of what I can do/check on my own before I go fight with them about this problem?
Here are 2 things I'm unsure of that may help a diagnosis:
1.) The brake pads have a very very slight rub when I jack the car up and turn the wheels (I've heard this is normal)- is it?
2.) Jacking the car up and spinning the rims while sitting eye-level with the top of the tire, there is a distinct dip in one section of the tire as it spins- it's very noticable. Could this mean the tires that bought (that only have 4500 miles on them) are bad? If so, then why did the original shimmy go away and why would it return now?
The shimmy/vibration is probably caused by a harmonic in the vehicle at certain speeds and road conditions(grit, grain, grading, etc). This is why it comes and goes.
Take your car to a shop that will balance the wheels ON THE CAR. This will eliminate any issues with hub offset to the lug holes.
Check all suspension components front and rear. Pay attention to ball joints and tie rods. Make sure all bolts are properly torqued, and if the nuts securing them are castellated (slotted) make sure the cotter pins are in.
Have the rotors checked for runout. Have the front hub bearings checked.
December, 15, 2011 AT 5:59 AM
Yes, brake pads will rest against the rotor at all times.
Your description of the tire sounds like a tread separation. This is a defect where the tread section separates from the inner liner. The new tire didn't have it until the heating and cooling cycle cycled a few times. This is a DTC issue to fix. Tell then when they fix the tire that you want a high speed dynamic on the car spin balance.
To amplify my thinking on the harmonic vibration, the frequency at which the suspension components vibrate gets to a point where the shimmy is induced, increases or decreases due to the shimmy and goes away. When the frequency of vibration gets to the right point again, shimmy. This is why it only occurs at freeway speeds, and not at other speeds.
Also check the mounts for the steering rack.
December, 15, 2011 AT 6:25 AM
I'll go to DTC tomorrow and have them look at the tires and balancing again with the high speed dynamic you mentioned. The idea about the heat on the tires doesn't really fit: they were rotated after the caliper problem- the rear tires are now in front and were never exposed to the extreme heat from the caliper seizing.
I just find it odd that all these problems started occuring after having Honda work on it. As far as the frequency that induces these vibrations- these are beyond normal. My entire arm shakes because the vibrations are so bad and it's never done this before.
December, 15, 2011 AT 6:46 AM
DTC may not have anyone qualified to perform that kind of balancing. It's old school high performance stuff. My recommendation would be to look around and find a shop that has an older mechanic that knows how to do it. Younger ones don't know how. It's pretty dangerous as compared to the normal kind of spin balancing on a machine that's normally done. It's surprising, but sometimes that shops that look old and ratty are the ones with the old timers like me working there.
Look under the car and check the CV boots. Make sure they're not ripped or torn.
Jack the front of the car up and wiggle the tires up and down. Then shake then as if you're trying to manually steer them through a tight slalom course. The up and down wiggle should have no discernible movement besides that imparted by the sidewalls. The in and out shaking of the front and rear of the tires should cause the steering wheel to move. One other test is to turn the wheel completely one way, firmly squeeze the steering rack boot and have someone shake the steering wheel about 5 to 10 degrees. You shouldn't feel any play in the inner socket, right at the base of the boot. Turn the wheel the other way and repeat the process. Use a small(-ish) pair of channellock type pliers and gently squeeze the outer tie rod ends. They should move no more than 1/8 of an inch with gentle pressure. If more, replace them. If there is up and down(or in and out at the top) movement beyond sidewall movement, the hub bearing can be failing, which can cause massive heat generation.
As I said, check ALL of the nuts and bolts on the suspension. Control arm bolts. Steering rack mount bolts and bushings. Tie rod ends. Steering knuckle. MacPherson struts, upper and lower bolts.