2004 LS430 UL with 126k miles. I am experiencing a rubbery sort of steering wheel shake over significant bumps. Ball joints and outer tie rod ends have been replaced.

What would cause this? Thanks.

 

Front Struts !!

 

Ya my struts are due for replacement and I'm getting the same issue.

 

I had the same and new front struts fixed the problem 100%.

Essentially your front shock absorbers are no longer damping adequately which leads to one side vibrating up and down more than it should and that leads to a vibration or shudder in the steering wheel after driving over a bump, sometimes even over a small ripple.
Mine started off only reacting to big bumps, but got worse as time went by. Then I got an "advisory" of oil weeping from the front right strut. Once the struts were replaced the car felt new again.
Mine has the air-suspension so I used aftermarket air-struts which so far are 6 months/5000 miles in and still feel great.

 

Which aftermarket struts did you use? Thanks.

 

Lexus OE. Only way to go, In the long run, you save money.

 

I used these. OE are stupidly expensive.
https://www.ebay.co.uk/itm/226720587264

 

I used similar air struts on the rear of my car. They’ve been on over a year and are still much better than what I took off. I have a pair of salvage front struts but am reluctant to use them. They would be 20 years old and have been sitting in my garage for a couple of years. 20 year old air bladders are probably not in good shape.

thanks!

 

Worn out Steering Rack Bushings. I had same issue with my 04, big steering shake after hitting bumps at highway speed. I replaced front struts and LCAs but no change. Then following advice found on Club Lexus I replaced Steering Rack bushings. Perfect 100% fix, easy DIY does not require alignment afterwards.

Part numbers, 2 per side about $60 ea. OEM. There are cheaper ones out there but I would stick with OEM

45516-50030 Drivers side
45516-50040 Pass side

Lexus does not sell these individually for 2004-06 (they want you to buy a whole new steering rack instead..WTF?) so you have to look under 2001-03 to find them...but they do fit all years.

 

Does it require to remove the rack off the vehicle?

 

You just remove two mounting studs. Unfasten the nuts then the studs unscrew from the frame. You don't need to remove tie rods or anything else. Advise having two sets of hands for reassembly, the rack is heavy and awkward. Look around on CL there is a "how to"...the tabs on the new bushings need to line up a certain way, check the procedure for instructions. Here are threads that help understand.

https://www.clublexus.com/forums/ls-3rd-gen-2001-2006/897336-daizen-steering-rack-bushing-installation.html

https://www.clublexus.com/forums/ls-3rd-gen-2001-2006/553981-steering-looseness-is-that-a-word.html