lensf415

Can someone plz help me figure out why my car shakes at about 50+miles in intervals?

It shakes, then it stops, then it shakes, and stops...its annoying.

It's not tire balance, because I did that, and it still shakes.

I'm assuming it's bushings, so has anyone had this problem before?

thank you

gs400Fan

try feeling the tires to see if they are even.

UZ214

u have stock wheels?

lex4

Try balancing the wheels

Alex

UZ214

i had to balanced my wheels couple of times(stock ones) to get the shakes away the shop needs to have a new hunter machinewith updated software...i am sure that will fix yr problem -uz

GSquicksilver

how many miles are on your car? i had bad vibration when i was above 60mph that the wheel would just wobble. i replaced my lower ball joints and caster arms. now everything is tight and vibrations are gone.

V300Graham

I too have been suffering badly from un-wanted wobble.

I read many of the previous posts in Club Lexus,
that touch on this problem, from one angle or another,
and very few of you seem to still have a wobble or vibration problem,
once the basic suspension wear items have been replaced...

I've replaced a lot of suspension parts on the
cars front axle, and she is a whole lot better,

Front axle LH and RH lower balljoints,
front axle upper arms
Front axle lower rear arms, (Castor arms)
front axle anti rollbar bushings.
Rear axle upper arms (2 years ago).

PLUS I replaced :

Engine mounts, propshaft centre bearing,
steering damper re-tightened to spec.
brakes calipers overhauled and tested for
matching heating up after long and short journeys
with a laser pointer type temperature gauge, etc

Parts alone so far have been very pricey.

Where is the BUT ?
Aha, here it is ! :

However, there is one aspect of it that I can't nail down...

She still feels like the propshaft,
or one of the wheels is damaged,

( but the wheels are new,
balanced multiple times,
and have the hub matching rings fitted)

It's a slow (and hard to identify) rolling wobble,
that builds up to a level that shakes the seat backs
at 60mph and again at 90mph and again
very badly at 120mph plus. (on a private road)
At 80 it seems to kinda cancel itself out, kinda.

It vibrates the whole car and this is noticeable
by the empty seat backs vibrating, and to a lesser extent
the steering column vibrating, about 30 percent of the time...

I'm thinking propshaft donoghuts, or a
damaged CV joint on the back axle,
but to go and buy those expensive parts
and still have it to happen,
would sicken me something awful.

I've tightened up the steering rack damper,
and it made a huge difference,
so I now think that I had a seperate wobble

As far as I can make out, the front axle is now sorted (hopefuly).

What is the current thinking on this problem in Club Lexus ??

Is there any one item,
that is left for me to change,
that may fix this problem ?

PS Congratulations if you read down this far,
thanking you very much for giving my problem
some of your time !

VNG704

bad wheel bearings?

David1969

I've tackled this problem by doing the following:

-replaced steering rack bushings
-replaced lower ball joints

The problem is still there, but not as bad. I still have to do the pre-tensioner, but i don't think that will solve the problem 100%. I'm having the same problem as V300graham in regards to the seatbacks shaking at the speeds he describes.

I know i have 1 rim slightly out of round and that's also contributing to the shake i feel in the car. Since i'm not the original owner of the car, i don't know what the car had been through, but it was a certified preowned vehicle. I researched the previous owner history with the tire shop that we both used and he had an extensive history of the front end vibrating. He always complained about the steering wheel shaking and the tire shop kept telling him that the tires were perfectly balanced. Still, the shake continued.

Under 60 mph the car rides as a Lexus should. Above that, and the ride is marred by this vibration. For long trips, we have to use the wife's minivan instead of the more economical Lexus.

tmf2004

iTrader: (15)

What is the steering rack damper? Are you talking about the pre-tensioner?

On that note if you read some earlier posts from lexforlife he has replaced just about every piece in the from end.. I think the main part is that caster arm.. thats were the majority of the vibrations come from IMO.. Ball joints will help but won't cure the situation..

THe daizen bushing kit, ball joints, tie rods, alignment and hunter balance is probably the first things i would address.. I've only done new ball joints as my car has low miles but i have steering rack bushings on the way..

BccGS300

I have had similar issues with vibrations on my 02 GS300. One thing to try is get up 60mph when the car starts to vibrate and step on the brakes. Does this change the vibration at all? Does it go away, get worse or stay the same? My vibration came from warped rotors and you couldn't notice until you got to highway speeds.

DCMango

You should describe a little more as to when you are actually feeling the vibration. Is it only at 50mph, or is it at other speeds?

There are a few possibilities -
- Tire balancing
- Tire
- Slightly bent rims
- Hub centric rings
- Wheel bearing
- etc

DCMango

Warped rotors should not effect vibration while crusing and or accelerating. Warped rotors should only be felt when braking.

BccGS300

This is true in most cases but on some cars, my GS included, you can feel a warped rotor without applying the brake. I resurfaced them and the vibration went away. Smooth cruising at all speeds. Luxury and Sports cars have tighter tolerances for wear-out items than your run of the mill sedan. Thats why its important to make sure that your maintenance is always up to date on these cars.

If the warp is severe enough.

V300Graham

Gents, you have made me very happy with all the responses,
thank you very much.

It looks like I will have to replace my front discs
as I'm having a severe pedal pulsation problem,
only during braking, indicating badly warped front discs
(the backs are fairly new) that I was quite happy to live with.
(Cost control)

I was thinking that it could not possibly,
IN ANY WAY, affect normal rolling resistance,
but after reading and considering your posts,
it's definatly an option now.

Sorry to keep harping on about this particular point of interest to me,
but.....
Has anyone replaced propshaft rubers or UJ's
or any drive train related items, even experimentally,
to assist with troubleshooting for this wobble problem ?

Now I have to have a look out for any threads
related to swopping the LS400 front set-up onto the car,
as I'm not about to go and put on another pair of
"easy to warp" GS300 discs on her.

Any further thoughts or pointers much appreciated gents !