turbotuner

iTrader: (1)

I took my '98 GS400 to the local dealership to have my 100k mile service done and mentioned I had a shake at 65mph and to be sure to look into the steering system and front suspension bushings during the service and inspection.

I got the car back and they didn't make any notes about it besides recomending a wheel balance, including not mentioning my leaking power steering rack I'm limping by on till I have time to replace it.

So I left it another day and had them put it back on the rack to look at the leak and verify it was the rack and not hoses/pump. I also asked them to check the tire balance if they were saying that's the problem since the wheels/tires were 3rd Gen GS350 wheels/tires off a CPO car that were balanced before I got them.

They claimed they were slighly out of balance and balanced them, but I still have the shake between 60-70 mph.

I have daizen bushings and new inner/outer tie rods and a new steering rack I was going to put in, but I wanted a dealer tech to verify that these peices were bad before I put in the time and effort... now it sounds like they're in ok shape since no replacements were recommended besides the rack if I felt like it, but they said it could just be monitored and I'd be fine.

So what's the best option? Is it worth puting on the new parts, or will I still have the shake?

Infamous 1

iTrader: (20)

Replacing the parts should def. improve the shake.

Rich23

iTrader: (3)

I'd say get a second opinion first. Secondly, if you have the parts you might as well chenge them, its always better to go new so if something fails in the near future you can rule out what you have already changed. All in all, good luck and keep us posted...

ZippyGuy

iTrader: (9)

Which daizen bushing do you have installed? The control arm bushing kit, steering, or sway?

Also, you might try the search function. The topic has been covered at least 3 dozen times. Here's a list of 12 comments to the same effect:

(https://www.clublexus.com/forums/sea...archid=5007004)

turbotuner

iTrader: (1)

I haven't installed any of the new parts yet, but I have all 3 in the bag. I needed an oil change and had it done at the dealer since I like keeping my lexus dealer history updated for resale purposes, and while I was there I just asked for the 100k inpsection of the car so I could use it to verify that the parts I planned to replace were actually worn and needing replacement.

I've always heard this car has a slight shake to it at speed, so if I'm just replacing good parts w/ newer good parts, I probably wouldn't notice much difference and the shake would still exist with new parts.

turbotuner

iTrader: (1)

interesting, I hadn't heard of a steering rack 'pretensioner' before... that would be worth playing with before replacing parts.

ZippyGuy

iTrader: (9)

BTW - I've been chasing down intermittent shakes successfully for years, here’s my process:

- Re-torque lug nuts to 75 ft-pd
- Still shakes, Hunter Road Force balance wheels (better than the dealership conventional balance)
http://www.hunter.com/pub/company/ne.../prGSP9700.htm
http://www.tirerack.com/tires/tirete....jsp?techid=40

- Still shakes, Hunter Road alignment
http://www.hunter.com/pub/product/al...tems/index.htm

- Still shakes, inspect hub barring (all 4 wheels)
- Still shakes, inspect and/or replace steering rack bushing (Daizen), you'll only do it once in the lifetime of the car
- Still shakes, inspect front suspension. Replace UCA and LCA with Daizen bushing), again, you'll only do it once in the lifetime of your car

As an additional reference, try reviewing the GS430/400/300 Service Manual as posted here on the site (http://bahamutcars.free.fr/workshop/...nts/index.html). Reference

SUSPENSION AND AXLE, TROUBLESHOOTING, PROBLEM SYMPTOMS TABLE

xfea

Been there - done that.

My shaking, vibration, knocking. etc. etc. issues went away when I replaced all my bushings with Daizen.

I did them all, rear sway, front sway, steering rack, and of course ALL the front control arm (caster !!).

While I was at it I put on Bilstein sport shocks all around.
Worth every penny - car track straight, NO vibration, solid sporty drive.

btw - it's nearly (no - IT IS) impossible to tell if your bushings are blown by just looking at them. In fact it is impossible to know if your bushings are blow by any 'inspection'.
I closely examined the old caster bushings while they were still in the car - and after they were removed. Without putting them in a vice and somehow stressing them to see if there might be a crack - there is NO WAY you can tell if they might be shot.

You have the parts - and your car needs 'em.

DO IT.

I also did the ball joints and tie-rod ends - followed up with an alignment.
Not cheap but turned my car into a whole new enjoyable ride.

Oh - a good alignment and good wheel balance are VERY important.


There is a one problem left - my car so gooood now I find myself driving way too fast....
I mean it feels great - even doing 125 mph+ on a road that was not an arrow straight highway...
(don't tell...)

GS4_Fiend

iTrader: (22)

I had the same problem like you and it ended up to be a bad wheel balance. Find a place that does road force balance and get it rebalanced. Start with the simple things first. Gl.

Newchapter

iTrader: (2)

I'm in the same boat.

99 GS400. I've replaced the bushings (including the sway bushings), balljoints, AND tie rods. I still get the shake (albiet less). Now I have a totally different issue. My car has an intermittent shake. Around 65 it starts and gets bad at 80. It will shake for 2 seconds and stop for 1. I hate it. Makes me hate this car actually.

white_ls

iTrader: (1)

I have the same issue, but haven't gotten to it yet. Mine starts to shake at 75 to 80, it's really is annoying.

Mike813

iTrader: (5)

I had the same shakes at one point in time and it turned out to be the tires. when i first bought the GS used the original owner had a set of new nexxen? tires installed and it had the same symptoms. did almost everything described above (balance,alignment, changed shocks/springs, the whole entire UCA was changed, ball joints you name it! spent well over 1400 on suspension parts since the car was used and im keeping this for a while so what the hell right? atleast im at rest knowing everythings new and wont fail on me. if you know someone local who DONT have the shakes swap out the wheels/tires for a test run on your vehicle it might be the same problem...

ivnnln

iTrader: (1)

I have the exact same issue and after changing the recommended list above, and balance all wheels. I didn't get shaking anymore. I got my wheels balance at America's Tire where I bought the tires. I did not tighten the lock-nut, just replace the daizen bushings for steering only. I might do the sway bar bushings soon. good luck with all of you for trying to tackle this chronicle issue.