JohnsRX

After a year and 5 months my RX has 12k miles. I did a 180 mile trip yesterday, driving as fast as traffic permits and i have some bad impressions.
We all know big wheels with low profile tires arent good for rattles and structure noises and comfort. But still i feel my car is pretty good at only 3 noticable rattles. But while going about 100mph yesterday, the car felt loose and especially under braking at that speed, the steering wheel shakes, hinting at a warp rotor problem, but doesnt happen at lower speeds. I can honestly say that i drive my car like a bat out of hell, I go full speed whenver traffic allows. But I DO NOT use my brakes too often, so i wonder why i have the warp rotors if thats the problem under braking. My car felt like shxx and very lose when i brake at hi speeds and i honestly thought i had a tire low on air or something. From now on, i think i will drive more like u guys and try to get that smooth feeling back again.

Sully C5er

100+ I wouldn't even think of doing that! I didn't buy the Lexus for high speed runs. IMHO it really isn't the vehicle for triple digits. I save that for one of our other cars, which is designed for running higher speeds. I have done 180+ a few times.

RX300SS

Slow down, the life you save may be mine!

///MDex

So when you do use them, you abuse them, thus, warped rotors.

JohnsRX

U got a point there, but i seldom use brakes period. I think i only use my brakes hard to a dead stop only 2 times! But maybe Lexus rotors suck more than most.

JohnsRX

i went 187mph last month in an RS4, it was rather un-exciting because the car was so good and stable. By comparison it felt better than the RX when its doing 90.

Sully C5er

It must have been modified to reach that speed. The RS4 is a little slow off the line, but I guess they are OK once they get rolling. I haven't driven one, nor see any at Road Atlanta, which is the only place I run hot laps. So where did you run?

JRB

Are you sure the vibration problem is due to the brakes/rotors? Could it be an out-of-balance situation, or something related to your oversized wheels/tires?

If it is the brakes, it would be pretty easy to have the rotors checked and replaced if needed. But it seems unlikely that they would fail at just 12,000 miles if you haven't been consistently hitting them that hard, as you say. Did you take it easy on them during the first couple hundred miles? Maybe they weren't broken in properly.

JohnsRX

It had a Wett chip and exhaust and it was on the freeway in Taipei. Since top speed is all the guys in taiwan cared about, i have seen more than my share of 187+mph there. The fastest i driven in L.A were around 160.

JohnsRX

Well, i thought of those things too, but it only vibrates when im braking at more than 80mph.

Jedi

I don't think it's your rotors, if it were your rotors you would definitely notice a pulsating feel when you go to stop. Such as at a stop sign or the like. It's typical for most people to warp the rotors with aftermarket wheels or when the buy the car new and haven't broken in the brakes properly. I can't tell you how many Honda/Acura rotors I warped by accident. Never get cool water (i.e. hose) on the rotors after you have just driven the vehicle.
Plus, if you don't use a MANUAL torque wrench you probably have over tighten your lug nuts, another great way to warp your rotors.
All that being said, I don't think it's your rotors, BUT if it is , I could understand why...per your own admission of your driving habits.
My advice...go to America's Tire Company....they will rotate the wheels/tires for free. And then get back to us and let us know if that solved the problem. Good luck. God Speed!