Steering Wheel Shimmy?

[ptkelly]

Great Forum...Need some help. Just bought a 98 LS400 w/ 85,000 miles and Lovin' it. I noticed that my steering wheel will shimmy when I hit the brakes but it only happens when I'm going 45 to 50 MPH+. Runs smooth and no vibrations while driving otherwise.

Any idea what the likely cause is????

Thanks,

PK

[pachocco1]

Do you feel a pulse at the brake pedal? or just at the steering wheel?

[ptkelly]

Just in the steering wheel.

[silvermate]

could be a warped rotar

could a wheel is out of balance

could be a bad tire

[99lsguy]

My vote would go to worn tie rod ends..........

[silvermate]

good thought Agent

also maybe the ball joints are worn out, thats very common.

[ptkelly]

Thanks 99lsguy and silvermate,

Maybe this will help to narrow it down.....Through research on this forum I think my sway bar bushings may be going bad as well. I hear small "knock" or "clunk" sound in the front right side of the car usually when I pull in/out of my driveway or going over other small bumps at low speeds.

With that being said, I'm leaning towards the tie rod ends mentioned by 99lsguy. Tires seem to be in good shape but could possibly be out of balance.....Not sure if the rotor is warped....I guess it could be.

Can you tell me more about the tie end rods???? Not sure what they are or if my sway bar bushing concerns could be related. Any idea on costs of repairs for these potential issues......I'm not a DIY.

Thx,

PK

[tansupplyman]

Note that the steering does have a steering dampner on it---shock absorber !!!

[99lsguy]

Thanks 99lsguy and silvermate,

Maybe this will help to narrow it down.....Through research on this forum I think my sway bar bushings may be going bad as well. I hear small "knock" or "clunk" sound in the front right side of the car usually when I pull in/out of my driveway or going over other small bumps at low speeds.

With that being said, I'm leaning towards the tie rod ends mentioned by 99lsguy. Tires seem to be in good shape but could possibly be out of balance.....Not sure if the rotor is warped....I guess it could be.

Can you tell me more about the tie end rods???? Not sure what they are or if my sway bar bushing concerns could be related. Any idea on costs of repairs for these potential issues......I'm not a DIY.

Thx,

PK

That 'clunk' sound is a CLASSIC SIGN of worn struts.....

stand over the front fender in the driveway and push down...a good shock/strut will bounce quietly back up with little or no "bounces",,,

The front wheel shimmy lists the suspect areas as follows:

tires

wheels out of balance

Shocks/ struts worn

bad alignment

worn ball joints

hub bearings

loose steering linkage

loose steering gear/rack

@ 85K, its entirely possible the struts, lower ball joints, and tie rod ends need replacement. It's a sad aspect of this car; but its also what gives it the remarkable smooth ride :D , Its the price we pay I suppose..... Like Silvermate suggested - lower ball joint wear is also associated - and a common culprit.

99

Here is diagram of the tie rod location - the tie rods are what's connected to the steering rack and cause the pivot of the tires. They "TIE" into the lower ball joint and wear occurs at the "ends or bushings".

99

comp.pdf

[tansupplyman]

If you can push your car down more than 1/8"-1/4", then the strut is bad or you weigh too much!!!! :D

I weigh 180# and mine is almost rock solid, without movement --on a concrete driveway.

[99lsguy]

If you can push your car down more than 1/8"-1/4", then the strut is bad or you weigh too much!!!! :D

I weigh 180# and mine is almost rock solid, without movement --on a concrete driveway.

Richard,

I just went out there and pushed down about an inch...I'm 185 lbs and a weakling :D The car just pops back up silently.................

99

[99lsguy]

Here are all the components...........

99

comp.pdf

[tansupplyman]

Roy--do you think it might be the KYB struts---I don't think I could make mine go down 1" if I weighed 300# !!!! SERIOUSLY.

Or may be difference in '93 vs '99??

Have a 70 BMW2800cs that will not move--like jumping on a concrete floor--it has Bilsteins.

[ptkelly]

Well, I went out and pushed down over both front fenders and I could compress each side about an inch or so. I weigh about 160 lbs. It went down and back up smoothly and did not reproduce the "knock" I sometimes hear.

Thanks for the diagrams and the advice. I guess I'll take it in to my mechanic and see what he thinks.

PK

[tansupplyman]

I would think a warped rotor-but doesn't take any time to clamp on a dial micrometer !!

someone who knows how do a poll on how far you can push your ft fender down---got my curiosity up.

[RCRFAN3]

I had the same problem with my 98 LS at 81,000. The right front rotor was .008 out of round, I had it cut and the problem was gone, Try this first its the cheapest place to start $24.00

[99lsguy]

Roy--do you think it might be the KYB struts---I don't think I could make mine go down 1" if I weighed 300# !!!! SERIOUSLY.

Or may be difference in '93 vs '99??

Have a 70 BMW2800cs that will not move--like jumping on a concrete floor--it has Bilsteins.

Richard,

I think you may be on to something with the Gen I vs III. Your LS does have a stiffer ride as Lexus has "softened" the cushion over the years.....

99

[lexur]

Hi 99lsguy,

Your PDF file is very knowledgeable to me who not very familar with car mechnics. How can I get the complete PDF catalog? Do I need to buy it or can download from Internet?

Thanks.