I have the same problem my sc its a 92 with 180k. I for some reason dont think its the rack, i dont see why they would wear in every car like that. Ive seen cars with 250k that the rack is fine. I just got new bushings, im hoping thats the real problem, so far from all the info i read, everyone says bushings are the root of this problem. It makes sense imagine if the entire rack shifts when u hit a bump, then it would jerk the steering...........makes sense

 

mine doesn't turn when you hit bumps but where they cut out old paint lines she wants to get in those groves ?? anyone have any ideas ??

 

These should help you with the steering rack bushings. You should replace these first since they are cheaper than the lower control arms.
https://www.clublexus.com/forums/sho...d.php?t=208313
https://www.clublexus.com/forums/sho...d.php?t=264932

As for the front lower control arms, you can have new bushings pressed in or just get the complete arm. OEM Lexus ones are about $400 per side for the complete lower control arm w/ balljoints. You can also use 93-96 Supra TT arms which are only about $200 per side, but probably provide a "sportier" ride.

 

i did the rack bushings, no help. i also think it got worse with my wider tires.
control arm bushings might help if you do both bottom and top.
i think this one will remain a mystery for a while

 

As with the bushings I have replaced them all except for the front uppers and I do think it is related to the rack...

 

i cant believe that as many people that have this problem. that no one know what the solution is. has anyone checked AllData? it normally has a list of common problems and solutions........

 

replaced my bushings yesterday, it helped a little, but the problem is still there. it must be the rack......... when i had the car jacked up, i could turn the wheels easily by hand, ive never been able to do that before on any car............

 

If you have ATF coming out under the boot, then yes you need a new rack. However, I think there are many people with this problem, where that is not the issue. The correct term for my problem is HORRID BUMP STEER

 

hey guys this might help. I just bought another sc300 and the suspension on this one is super tight. The power steering rack has been replaced by previous owner with an entirely new oem unit about a month ago, meaning new bushings as well.

The car is a 5spd and the power steering doesn't seem to be as strong as my other car with an old rack+new bushings. the steering is nice and tight, almost perfect with the new rack.

so i took it to the road in dc that always makes my car swerve right when i hit the bumps (K street and 17th street). EXACT SAME THING HAPPENS IN THIS SC!!
I was hoping it wouldnt, but it did. exact same bump steer on a brand new rack.

I dont know what does it, I would be surprised if someone finds a fix for it.
Maybe send a letter to your senator to fix the bumps in the road?

 

interesting..........

 

maybe its just the road is messed up.. lol.

it is definately seems less severe in the car with the new rack, if that helps anyone

 

Under further trial and error, I went ahead and swapped out the upper control arms. It seems to have corrected the problem. I will further inspect the ball joints from the arms that are now off the car. I will continue update my findings after driving some more especially on the highway and coming to a moderate-fast stop on a bumpy, uneven road surface. So far the car seems to stay straight while driving unlike before. I have not replaced the rack yet, just the upper control arms and I do notice a difference so far.

 

any updates? how big of a difference did that make? it makes sense tho!

 

how much did you get the upper control arms for?