I just noticed that on my '99 when applying the brakes, I can feel a very slight steering wheel vibration. No vibration during accélération, slow or fast Driving -- just during braking. Car drives as straight as an arrow and no noise coming from the suspension.

4 wheel alignment was just done about 200 miles ago.

I dont feel any vibration from the brake pedal and car stops with no problems.

I've used the search function but i could not find à thead that talked about steering wheel vibration only during braking. Maybe i did not use the right keywords.

What the possible cause of this issue? Any particular suspension part(s) I should check. Thank you.

 

Strut/caster bar bushings as well, worn UCA or LCA arm bushings. The other usual check to verify rotor run-out would also be applicable. Varies though seems that 70-100K miles on these bushings is pretty common.

Miles on car?
When/if the strut bar bushings were replaced?

 

Car has 146k miles. I bought the car about à year ago but I only put roughly 3k miles on it so far.

No idea if any of the bushings were replaced.

Do you suggest replacing all these bushings mentioned for good measure?

Where's the best place to buy these bushings ? Price and quality wise.

 

I agree with RA40 - new strut bar bushings (make sure you use the real Toyota part - it's cheap

next most likely is upper control arms (Toyota part is very very well made but prohibitively expensive and I am not sure who currently makes the best aftermarket one, search for thread on the subject here on Club Lexus!)

 

Steering wheel vibration while braking is almost always front brake rotor warpage.

 

were the wheels balanced as well or have been recently with the alignment?

 

It sometimes is - especially on the 90-92 LS400 which has brake discs that easily warp - but the 95-00 LS400 is "special" with its odd, less than desirable front suspension design. At 167,000 miles, my 2000 LS400 is having a slight wobbling vibration on braking as it did before I had the strut bars/bushings replaced at 86,000 miles.

I should, if scheduling "clicks", be having my front strut bar assemblies replaced and an alignment performed this coming Friday. I could probably live with the minor vibration but I know from my previous experience that it is only going to get much worse.

 

OK. But I dont feel any brake pedal pulsation.

The wheels were balanced and aligned recently. Maybe I will have them recheck since I bought lifetime balancing and alignment.

 

I don't have any clunking noise on the front end when hitting bumps. I thought this is the main symptom when a strut bar bushings goes bad.

 

I would do a quick rotate of the wheels and see if this changes the vibration you see in the steering wheel. If it does then you know one of the wheels needs to be balanced again. I have read that the LS400 is sensitive to wheel balance issues.

This literally just happened to me. I was searching all over for worn out bushings/mounts etc only to realize I should have just rotated the tires first and eliminated the obvious.

But your vehicle may be experiencing something different. I had vibration at 65mph (not above 70, not below 60) and during braking.

[edit] - also now that I think about it the alignment shop should have been able to point out anything on the suspension that is worn and needs replacing. FYI

 

Thats sounds like a great suggestion -- quick and easy.

The alignment shop did check for worn parts before they did the alignment and they did not mention anything.

 

Brake pedal vibration is from rear warped rotors. Steering wheel vibration is from warped front rotors. Their cheap at Advance Auto Parts or AutoZone. Just replace them dont have them turned down.

 

and what, exactly, is wrong with having brake rotors turned?

 

I am not much of a fan of turning rotors either (as Kansas knows) although this would be a case for it!

My money is on the tires themselves or the balance of those tires.

I had this same symptom, pulsing in steering but not through the pedal and a new set of quality tires (i.e. Primacy, Serenity Plus, etc.) and a road force balancing completely eliminated the problem!

 

I will have these tires rebalanced and go from there. Thanks for all the great input.