I think you can replace this part if it loose or play like 1/2" or so. 4526030080
SHAFT ASSEMBLY, STEERING INTERMEDIATE, NO.2

 

Zip tie cost $0.50

 

Ok I finally got in the updated bushing for the steering rack in play. (even though the spring is on back order so I reused the old spring by adding a spacer)

I think what Lexus was trying to do is get good steering on center without adding a lot of Caster. This way you get the best of both worlds (or so they thought) so they used rolling friction to preload the rack rather than sliding friction in an effort to reduce the friction. This in turn makes it sensitive to incoming vibration because it takes out the damping effect, Probably what was added with the Zip tie trick.

The first two images are the roller method that originally came with the car (I have a 98GS400) the last image is the update, A plastic piece that clips in the metal piece. (sliding friction instead of rolling friction)

Steering feels better dampened but have not driven it long enough yet to make an assessment but this follows along the theory I was thinking in my previous post. So far I like the way the steering feels.

So after you have fixed all the worn bushings, ect... this should put the Icing on the cake to just get rid of that tiny bit of vibration that is left under certain road conditions and speeds.

(sorry for the quality of the pictures)

 

Update,

I got the rest of the parts ( spring, wave washer, bolt) what a difference! Steering is rock solid. Very nice improvement. I can finally say I am 100% vibration free. If the adjusting nut is an outy (hex is like a bolt) then you have the old roller design. If your adjusting nut is an inny (like an Alan head) then you have the improved design.

 

So since then, i've replaced all the tires, brand new wheels, new rear suspension (coilovers), re greased the ball joints and installed 18mm front RCA's.

I get a very mild shake from 65-70. Then mild shake at 80.

I'm going to get the front wheels re balanced tomorrow. Mine has to be a balance issue, as when I had my stock rims on for the last two weeks I had no shake at all.

 

Update:
I did the zip tie method on the steering column and it eliminated the rest of the 60-80 mph shake. I can tell some of it is there due to me looking to feel it during the mph range but it's gone.

It also tightened up the feel of the steering.. feels like a new car. Love it.

 

my car shakes early in the morning or when cold. ended up being tires need to warm up and the shake went away after driving it for awhile. weird right?

 

Whats the psi? You should examine/measure the tires. If really your driving is causing them to heat up. You may want to raise your psi, as the current settings are creating significant friction to generate the heating. So you are losing mpg

 

+1. I just did the same thing. I also have the SD steering ECU. Steering feel is amazing...

 

I also have the SD ECU as well. The tightening for the steering shaft just enhanced the SD ECU. Great steering feel.

 

Do you guys have the inny or outy on your rack play adjustment nut? Because if you have the outy then you need to update your bushing in there. The zip tie essentially is the same thing. Please tell me wich you have inny or outy thanks

 

I have an inny.

 

I wonder if that plastic bushing wears out over time because you should not need the zip tie. Unless your bushings on your steering column are worn out

 

I'm thinking its my 19" wheels. They may need to be road force balanced. Or the lower profile tire is causing the car car to shake. It did not shake with my 16's.

 

What years did they manufacture the update?
I think I may have the outy