juniortai

so i have clunking noises when i do go over bumps... two different mechanics checked out the ball joints and they said they were ok, nothing wrong with suspension overall.

what could it be? shocks? haven't replaced those in... forever!! what do old shocks sound like? anyone know?

Thanks for your input!

Charlie aka JT

fatchance

This is my 2nd GS and I had a similar noise that was solved when one of the upper control arms was replaced.

My newer 99 GS300 with 110k miles just had both the upper control arms and lower ball joints replaced. I had a 4 wheel alignment and wheel balance done. I still get a clunking noise most apparent when going over New England washboard/frost heaves. My mechanic has not had a look yet but thought it might be loose brake pads. It's not the brakes cause I still get the noise if I use a little brake pressure.

I spent so much money on the recent front end work I just want it to be at least as smooth and tight as my beloved 98 GS400 before I totalled it in a snowstorm 2 months ago.

I really could use some help figuring this out.

sivikvtec

check your lower control arm bushings.

fatchance

Thanks for the tip

would those not have been replaced when the upper and lower ball joints were replaced? I'm not a backyard mechanic and I'm confused by the fact that the upper control arm is part of the ball joints.

lextechGS

iTrader: (2)

My guess would be either lower control arm bushings, or caster arm bushings (sometimes also refered to as strut bar bushings). Daizen makes a bushing kit to replace all of these. Lastly, if it is a brake pad noise...make sure you have factory shims on the front brake pads. Brake pad shift noise is also heard the first time you apply the brakes going in a forward direction, after you have have backed up out of a parking spot and hit the brakes. It is noise caused by the up and down movement of the brake pads.

fatchance

Just to be sure. What bushings get replaced when the upper control arms and the lower ball joints on both sides get replaced with OEM parts? Would these bushings cause vibration at 55-70mph? I've had a 4 wheel alignment and all wheels balanced and I still get a pronounced vibration at highway speeds. It goes away over 80mph though. It might be the snow tires though.

Also are new OEM parts upgraded from the original 99 GS parts? I think I read they are now the same as what came in the GS430.

Thanks again for narrowing this down.

lextechGS

iTrader: (2)

When the upper control arms are replaced, it includes a new ball joint and bushings on either side of the arm. The lower ball joint is just a ball joint....no bushings involved. I don't think these parts cause much vibration. Mainly I believe the caster arm bushing is responsible for vibration around 55-60mph. I replaced all my front bushings with the Daizen control arm kit. My highway vibration went away completely. First I replaced the caster arm bushings, and I noticed a much reduced vibration while driving. Next I did my lower control arm bushings, that pretty much took care of the rest of the vibration, along with adding a much more solid feel while cornering.
As far as the OEM parts being upgraded, I am not completely sure. I don't think much if any change has ever been made to them. Also, I think all 2GS models share the same upper control arms and lower ball joints. I may be mistaken, but they look identical. Hope this helps

sivikvtec

They updated the caster arm design and bushing. Theres a thread on here about the updated arm design and TRD bushing that came on late 2GS's.

12ax7

you guys are great. Is Daizen the only option or are OEM bushings ok? Is this a simple job that any decent mechanic can do or do I need to get a lexus guy to do it?

Daizen seem to be backordered at Sewell quite alot. If I do buy the Daisen kit do I have the mechanic leave in the brand new OEM bushings that need a lot of labor. What do you suggest?

sivikvtec

I don't believe in using poly bushing on a car like a GS (transmits more nvh into the cabin, can squeak without grease..etc). The updated caster arms use TRD bushings which are an improvement over stock. The arms themselves are also beefier. Check out this thread....

https://www.clublexus.com/forums/sus...ml#post5011972

fatchance

Sorry to be thick but are you saying the OEM bushings cannot be replaced with OEM bushings?

1-The whole are needs to be replaced or

2- Diazen bushings to replace worn out oem's using the original arms

Is that right?

Thanks again,

Sorry for the 2 user names. I forgot my older user name

fatchance/12ax7

sivikvtec

the most likely culprit is the caster arm, the one I posted the link to about the arm differences. Toyota does not sell the replacement bushing by itself (so if you went the daizen route, you would press a new one into your old arm). The new updated OEM arms with bushing are about $130/ea from carson toyota. The other bushing which may need replacement is the lower control arm bushing, it is available by itself, about $17/ea from carson toyota.

fatchance

It's fixed!! My mechanic found that the bushings on the stabilizer bar were worn. He replaced part # 48815-30480 for $40 plus labor and that along with a competent wheeel balance finally fixed the 2 remaining issues I had.

Thanks for all your help guys.