To make this as short as I can.

Had a situation come up where I locked up the brakes and left skid marks for MAYBE 15 or 20 feet. Now - when I first start driving my car in the AM - everything is fine. Then after a few miles I start feeling this vibration in the car (steering wheel, gas pedal, etc.) and I hear a slight (grinding?) noise. I think it wouldn't even be noticed if someone else were driving my car. I think it's getting worse. This started right after I locked up all four wheels. Any ideas?

 

more of your tires. Or when you were stopping, were you trying to avoid hitting something, like a curb, but did not actually avoid it. In other words, did you actually hit something that may have knocked your front-end out of allignment. Seems like 15-20' of skid marks should not have flat-spotted the tires. You may have to move tires around to issolate which tire is the culprit.

As far as the grinding noise, that seems unrelated to the skid marks. You have have to give a more in-depth report to diagnose that one.

 

Maybe you glazed the rotors. Get them checked or shaved.

 

I thought that a flat spot could cause that but the only thing that didn't seem right was the fact that this only happens after everything has warmed up. I can haul butt on the freeway while the car is cold and the vibration and noise isn't there.

 

More clues are needed. If this grinding sound can be heard at low speeds take an assistant to a quiet parking lot. Have the assistant stand in the lot while you drive by. Ask if they can hear the sound and, if so, identify which wheel the sound comes from. Then have your assistant drive while you stand and listen.

After this evidence-gathering exercise focus attention on the suspect wheel.

1) Verify that all wheel nuts are tight.

2) Raise the suspect wheel. No need for jackstands, as you will not get under the car.

3) Grab the top of the tire (12 o'clock) and push away from yourself and pull toward yourself. Yank it to and fro in this fashion several times. If there is noticeable free play or a "clunking" sound, the wheel bearing may be damaged.

4) Spin the wheel. If it spins freely but makes ugly sounds the wheel bearing may be damaged. If it won't spin freely the brake may be dragging. This could indicate a sticking caliper.

5) Remove the wheel. Make a careful visual inspection of the brake and surrounding parts. See if...
- the stamped sheet metal baffle plate has been bent and is rubbing the rotor
- a pebble or other foreign body has become trapped and is rubbing the rotor.
- a brake shim has slipped out of position and is rubbing the rotor.

This slipped shim possibility may have a tie-in with your panic stop experience.

 

listen 2 this guy. he knows what he's talking about.

 

Very cool - thanks Daniel - I will do all of that this weekend.