Lex-Toyo

My '98 GS400 has 20k miles on it and the previous owner didn't drive it hard at all. When I apply moderate brake pressure when travelling at higher speeds, I get a vibration in the steering wheel. Someone suggested that the rotors might be warped. Someone else suggested that the vibrating could be do to fading. The tires may be the second set on the car Mich. Pilot (xgt?) 8/17... Stock wheels. Were these offered on '98 Gs4's? If not, then have the rotors warped (slightly) because of one tire change, alignment, or balancing? Is it that easy to warp these rotors? Or is the vibration due to fading, or my driving it hard or whatever else? It is not that bad where I'm too worried, but I would love to learn more about what could be going on here so maybe I could avoid problems. Thanks for any imput!

RealMarty

The 98 GS400 with 17" tires came with Bridgestones as they do now. If you have Michelin's they are not the original tires. Actually, this is not unusual since the Bridgestones don't last long (13k-18k is about it and 18k is unusually high).

Are you feeling any vibration in the steering wheel or the seat of your pants while at high speed? If so, braking is just amplifying an imbalance, out of alignment or other suspension problem.

One thing to try is to loosen the lug nuts on each wheel and re-tighten them using the "star pattern" technique to see if the wheels have been tightened incorrectly and have introduced an untrue rotor.

I've occasionally gotten the same vibration on my car but it seems to go away after a few seconds on the brake. I just never worried about it (probably since it does go away so quickly and also since the car's leased and I'm turning it back in June).

duster

When my 98 GS 300 had about 12,000 miles on it I noticed the same thing about the vibration when the brakes were applied. The dealer replaced the rotors for me. They said they were replacing them when this problem happened within 10,000 miles. They said they were doing me a favor since mine had 12,000.

It sounded to me like this was some informal TSB or something. Anyway, they took care of it and I was happy. By the way this was at the notorious Glendale Lexus. They took care of me on this one.

You might want to check with your dealer and see if there is something special they can do for you.........Good luck.
Ron

gs4power

Hi Lex-Toyo,

I think the vibration you're having is brake-rotor related. By your description of the previous owner, I doubt the rotors are severly warped ( they don't need replacement), but it is likely they've worn out unevenly. You may try a relatively inexpensive alternative: Have your front rotors resurfaced by a reputable machining shop (Be sure they have experienced personel and check if their lathe is well mantained-this is critical) and get new front brake pads from the lexus dealer. I'm sure this is the solution of your problem. Good luck!

chowder

99 GS400, 20K miles on original 17" Potenzas
I've gotten this high speed braking steering wheel vibration you mention, but only noticed it lately. I've blamed my very cut/run-out stock tires. I'm replacing them now. If the vibration continues thereafter, I'll suspect my rotors and be having a sit-down with my dealership...