RalAegidius

Trivia for today: They're called "Botts Dots". They were invented by Elbert Botts, a California chemist working for CALTRANS in the 1950's.

http://www.snopes.com/business/origins/bottsdot.htm

Ral

tn52

Make sure that your bushings are OK FIRST BEFORE trying another set of wheels & tires. Check for any looseness & play in the bushings/suspension/struts. If you don't, you may end up chasing unrelated problems other than the obvious culprit... By the way, do you feel the vibration on the steering wheel or from your seat?
Good luck

ChrisK

iTrader: (1)

TRM04,

Buy the canister of T-IV transmission fluid, $24, and change it yourself. It should take about 2qts or half of the canister. Make sure that you put enough fluid in but do not over do it.

GSquicksilver

check your rims. are they chipped heavily? could be ur rims could be out of weight balance if they are chipped. my old ls400 had rims that had these major chips in them, kinda looking like someone ripped the edges off. and it had a similar feel to the description you describe. got new rims, solved everything. but my shuttering came around 80 mph.

VQT

Need to find out did they (the dealer) flush the trans or just replace 2 qts. (how much did you have to pay, price will tell)
Like ChrisK mention, buy a can or two Toyota type IV trans. fluid and change it yourself. If you can get to a place that flush the fluid then it would be better.
To do it yourself is very simple, just like oil change without the foil filter hassle.

Call Steve Ganz or Gordon 800-908-6968, ~$20 a can

Pyrotech

i had a similar problem and still do. i have a shudder between 30-35 and then again at 75-80. at 80+ it goes mostly away or if i accelerate by flooring it there is no vibration at all. ive been to the dealer lots of times and my mechanic. it started out that i was told tires needed balancing, then an alignment, then new tires, then rebalancing those and realigning those. then the engine mounts got replaced. still vibrates. then they say my driveshaft is out of whack or it may be my air struts which are at the end of the road at 99k miles. so, i am left with the same problem you are. im going to replace the front air struts first because they absorb almost no impacts and the car drives all over the place. but i do remember reading in the Townhall on Edmunds.com about halfshaft problems causing those vibrations also. guess Lexus just wants me to replace everything. they said about $7000 a few months ago and i said thanks and walked out. a few bushings later and mounts later it still shakes but i'm going to get the parts replaced a little at a time with parts from irontoad.

pyro

VQT

Did you change the trans. fluid? I had the same problem and it got worst and worst until I changed the trans. fluid. The problem is gone.
Why not try the cheapest route first

TRM04

His problems sounds similar to mine so I highly doubt that'll be it...but hey it's worth a shot.

AAM

ChrisK

iTrader: (1)

If Lexus dealer did the T-IV fluid change, I'm pretty sure they only did 2 qts. The dealers in the Chicago area do not do full flushes because they don't have the equipment to do so. When I was looking for the place to flush mine none of the Lexus dealers, and I called around, could do it. Finally I found the Toyota dealership that was up to the challenge.

I asked him to change 2 qts by himself, because when doing it he would be able to tell if it helped or not. Then if he sees the improvement, then he can go for the full flush that will most likely cost around $200.

danynijm

The problem that you are experiencing is a common problem for pre 1998 LS400 and SC400 because they share the same engine and troque converter.

There is a problem with your torque converter. It feels as if you are running over a wash board at certain speeds. I had the same problem when I picked up my Certified 1993 SC400 in 1997.

If you search the forum, you will find threads of people with the same problem that you are having.

TRM04

The mechanic suspected the same thing. He ran several tests on the converter while driving and they passed...according to him. Mind you, I was in the car with him and I too agree that the converter passed his tests.

Wheels go on tonight...we'll see what happens...

Thanks.

AAM

Pianoman72

You're going to want to attach these metal weights to your steering wheel like so. C'mon guys, everybody's doing it these days!

whitels

Nobody has suggested of a possible issue with the propeller shaft. I had the same situation about 15 years ago in a Supra, 5-speed. The technicians at Longo Toyota diagnosed the problem as an out-of-balanced propeller and replaced the thing under warranty. The problem was accompanied by a very small leak in the rear transmission seal. I guess the tiny play brought on by the shaft allowed trans fluid to seep through the seal.

wwest

Out-of-balance. Not really likely since the symtom "comes and goes". As I already said it is most likely the needle bearings in the propeller shaft u-joints. It is not at all unusual to develop a few "flat" needle bearings, especially at high mileage, and the effect is not felt unless they have "momentarily" rotated within the asembly to a high bearing stress area.

whitels

The fix by wwest is most likely if the trans rear end seal is not leaking oil.