rja400

I've had my 99 GS400 for about a year and a half. When I bought it, it had stock Chrome Wheels in OK shape with horrible H rated tires. Not too long after buying it I started noticing too much road noise, steering wheel shake, and seat of the pants shake at 50 - 80 mph. I chalked it up to the bad tires, and bought a set of take off 16 inch factory chrome wheels with Pilots, that had next to no miles on them.

While much better tires, I still get waaaay to much (for a $50k car) noise and shake in that 50 - 80 mph range. It goes away briefly when I take my car in for the 5k service (they rotate and balance), but is back within 500 - 700 miles.

I love the comfort, accelaration, and look of the car. Hate that I feel embarrased when people are in the car with me at freeway speeds, the "warble warble" of the tire noise and the vibrations grating at my nerves. I found myself (horror of horrors) at the toyota dealership the other day looking at the new 280hp Avalon and thinking of trading in my GS400.

I'm sure lexus knows something of this, since why would they recommend rotating/balancing as often as they do, but that's not enough - I'm losing patience with the car.

Does anyone have any ideas as to what to try?

Thanks a hell of a lot.

chuckb

search for steering pretensioner among other keywords

J.P.

Check your rotors\calipers. i had the same thing happen. A caliper was sticking. Replaced the caliper and all was good. I had 2 sets of wheels at the time and was like WTF.... Caliper fixed it

rja400

OK, after searching and searching on these forums, this is what I've come up with as possiblilities...

1. Tighten steering pretensioner (I think they did it already, I guess they can do it a bit more). Seems to help, but not take away problem?

2. Replace front rotors (problem is at speed, not while breaking, but perhaps the worn rotors can affect an already delicate front end?)

3. Sticky caliper?

4. Steering Rack Bushings?

5. Lower Control Arm Bushings?

6. Get rid of wheel locks?

I would imagine that options 2, 4, and 5 would cost some serious coin to just replace to "see" if shaking goes away. It seems like this is a major problem among GS owners, I hope it doesn't drive me to be an ex-owner!

DaveGS4

iTrader: (2)

You missed one that will also help... get a road force balance on a Hunter machine.

You could also have a bent rim and / or the mechanics are using an incorrect torque spec on your wheel lugnuts

Guitarman

Ditto on what Dave suggested. You'd be amazed at both how poorly a lot of shops do a simple balance jobs, and also how a regular computer balance doesn't really cut it anymore for most modern cars that have sophisticated suspensions that transmit more feel, and 17" and larger wheels.

The Hunter balance machine matches low and high spots on the rim and tires and can verify if a rim or tire is out of spec. Do it, it's ~$20 or so a wheel, but worth it. Good place to start at least.

I know just how you feel, I can't ( and won't) tolerate that in my cars either. The Hunter machine is your friend. Discount Tire has them, among others. Good luck.

NT2SHBBY

been there done that....still got vibration....I believe these cars are inherently born with it and dropping them makes it that much worse/more noticeable...

and it's not vibration that is constant.....it comes and goes

varcity64

iTrader: (2)

definitely NOT always true... i myself had this problem, but after re-balancing the tires, vibration went away... and then i dropped my car to NO GAP all around and still no vibration. now there are ALWAYS special cases and it does seem to be more common than it should be on a lexus, but it is what it is, and i would recomend trying this 1st before anything else. good luck

highmiles

Sounds like the Rotors need to be faced or or possibly replaced. I have had the same problem on my 98 GS400 (16" tires) with 300K+ miles that I would notice especially on hard braking from high speeds. I eventually would always make it a practice of turning my rotors every 40-60K miles until they needed to be replaced.

Also those Pilot tires were the worst set of tires I ever had on my 98GS. I have had 2 sets of Bridgestone Turanza LSZ Tires that are VERY quiet and smooth and the best set of tires I ever had.

flashbang

check all that and then check your wheels (rims) could be bend .It happen to someone I know ,thats me.

rominl

iTrader: (4)

yes, among the 3 lexus i have the gs400 definitely has the worst steering of all, even modded. it's just loose i don't undestand why. and i already have heavy suspension with tightened steering wheel pretensioner. at least i don't have the vibration anymore so i am really happy about that. that's all gone ones i get the new steering wheel pretensioner i believe

NT2SHBBY

been through THREE (count em THREE) sets of OEM wheels (TWO BRAND NEW SETS, one existing) -2 17" sets and one 16" set

all balanced with hunter machines, lugs torqued down with torque wrench to 70-80lbs of pressure


I still get vibration, and its NOT ALL THE TIME!!! it comes and goes


I'm convinced it's inherent with this car

and my front rotors were replaced by the Lexus dealer about 5K ago

Blue98Gs3

iTrader: (1)

There is something wrong then, you should not be having a shake.

I've heard that the 17" wheels are almost impossible to get balanced completely, as when I had mine they had a shake, then when I jumped to 20's, the shake was gone.

J.P.

"I still get vibration, and its NOT ALL THE TIME!!! it comes and goes"

Mine came and went to as the caliper was sticking and sometimes not. You don't have to replace it, just have a brake shop check it out.

chuckb

17s are hard to balance? harder than 18s or 16s? why?