GS69

So my 2006 GS300 has been shaking/vibrating when I decelerate (not using the brakes, just taking the foot off the gas) during highway speeds (65+ mpg). I took it to a mechanic & he said that it was the alignment, which he fixed but the car still does it. Does anyone have any ideas on the cause/fix? A quick internet search shows that some people believe it to be rotors ... ? But some don't.

Thanks!!

07LEXPL

I've been asking the same thing for a long time.
i have a 07 gs 350 awd, lowered, and on staggered rims.
Took a lot of trial and error. changed brakes/rotors, tires, ballpoints, barrings, control arms. nothing.

FINALLY i found out it was the front left CV Axle. But then again not sure what your setup is.

Try this, when you decelerate wait a second then slam on the GAS if it vibrates too then its your axle.

i found out it was front left by really looking close to see the rip in the boot. can't tell just looking had to move them around.
when replaced with napa rebuilt (way cheaper then dealer new) Lexus smooth again.

Hope this helps.

GS69

I tried your suggestion & the vibration did stop when I pressed on the gas. Hopefully the dealership service can solve this issue.
Thanks again!

07LEXPL

One more thing, if its AWD and if your running staggered rims/tires then let a little air out the rear tires. Something like 35 rear 40 front this will help equal out the diameter of the setup. front has more weight so tire will be more compressed resulting in smaller diameter. less air in rear helps compress rear tire to match. Good Luck..

ibidu1

iTrader: (1)

No matter how much air you release your still at the same tire diameter.

07LEXPL

if front tire is compressed more then rear your telling me its same diameter. take a tape measure roll over it and measure front then rear, if you have same psi in both, rear will be bigger.

Bhdien

iTrader: (1)

Mine did the same thing. Changed rotors, brakes, balanced wheels and all. Finally decided to check on the engine mounts just because I remember my BMW doing the same thing. Odd, but replaced the engine and tranny mounts and the shaking went away. This may not be the case for you, but if you checked all other items, I would look into the mounts.

GS69

I really appreciate all of the tips/advice! Mine is a RWD, not AWD, btw.

Unfortunately, the car was hit in the parking lot (of course they did not leave a note) so I am currently dealing with that. This is my 3rd hit & run @ my work/school parking lot & I am anything but pleased.

Thanks!

ibidu1

iTrader: (1)

If both front and rear tires have the same OD height then yes.

Outside diameter of the tire does not change. If you grabbed a tape measure to the OD of the tire it will be the same no what matter the psi. Only way to change the OD is if you take material off the tire.

You lowering air psi only lowers the height of the wheel, closer to the ground. You still would not effect the OD of the tire as the OD still has to roll.