After doing a search and reading thru 2 pages of results I decided to ask the good people on the main board...

My 98 GS400 with 110k miles vibrates between 50 and 60 mph when accelerating (stops after 60) and even more violently when braking from 60 - 50... I have 4 new tires (6 months old), stock 17's, had wheels balanced, rotated, and aligned 2 weeks ago, rotors (rotora slotted) 2 yrs old... Does anyone know what could be causing this? I read somewhere years ago that vibration could be fixed by tightening something on the sterring column couldn't find thread again...Any help would be appreciated...

 

Try checking the lower ball joints or looking at the caster bushings.

 

Brand new lower ball joints about 10 months ago...Caster brushing? hmmm off to the search function I go...

 

...do a search and I think you'll find many articles and posts on the topic.

good luck!
dd

 

Steering Vibration - Just fixed this on my younger brother's GS400 last week.

See attached documentation.... documentation is on how to replace the bushing and etc... instead just use the step where it talks about installing it and tightening it. We were able to use a pipe wrench and customized bolt converted to work like the key since it's hard to find such tool. But it worked for us and he no longer has vibration.

Some other info...
- if u tighten the bolt to much then when you drive and turn the steering it will not come back automatically, that mean u over tightened it.

Hope this helps........ it's very easy and simple procedure.

 

vibration from when braking is usually warped rotors..

 

yup- 2 years is plenty of time for rotors to warp.

also, were the tires road force balanced and what are the numbers? hopefully they are 24lbs or less, otherwise that could be it too.