Hello, I have a 98 LS400 with 138K miles and it has been making clunking noise when going over potholes (sounds like the suspension bottoms out of something). Not too much over speed-bumps. I also hear slight clunk from when turning wheels at stop. I have done a few searches and see anything from bad struts, bad strut bar bushings, ball joint bushings, to sway bar bushings. One posting really caught my attention was about tightening bolts under sub-frame. What is it? Has anyone else done it?? I took my car to a mechanic and he checked the wheel-play and bushings, everything is good and tight - so I was told. I hate to start pouring money into changing things that did not need to be changed. Any help is appreciated!!

 

Does it happen when the front or the back goes over the pot hole?

 

front strut rod bushings. search on it. 9/10 times. (front end obv)

 

"I also hear slight clunk from when turning wheels at stop."
Although a rear steer LS would be awesome I don't think it's been done.
Everything you mentioned that you searched for could be a possibility for your clunk. As PD said, check the strut rod bushings, (front) it's a very common problem. (strut bar is in the rear) I would get a second opinion from a different mechanic. If you have a clunk then there's something wrong, the first guy just didn't check it good enough. You can check it by yourself (with a helper) by jacking the front end up, put a bar under the tire, and try lifting and moving the tire while you (or your helper) is under the car looking and listening. If the mechanic checked it on a lift there's no way he can put enough pressure to lift the tire to duplicate the noise. Just b/c the bushings look good doesn't mean they are good.

 

pwned by reading

 

I replaced my strut bars/bushings and ball joints trying to fix my clunk, although mine clunked over speed bumps as well. Oddly, it noise went away in the summer and returned when it got cold again. I was not able to find out what was causing it before I got t-boned by an old lady.

I remember reading about the subframe bolts and that's exactly what I would do first since it doesn't cost anything.

 

slightly subframe bolts dont cause the same creaking/clunking sounds sound you get from dead front strut rod bushings, they give more of a click/thump iirc.

 

Does anyone have the part number for the front right (passenger side) strut rod ??

Mine has gone bad & hours searching has yielded me everything except the part number...

 

Is this for the '99 that's listed in your sig?
Actually the front is a strut bar. The part # is 4866040021. It can be found at Sewell here; http://lexus.sewellparts.com/oem-cat...S400-1999.html

 

first off, the crossmember in question is the one your rack is on. tighten it up....
and as PD said probably SRB's are bad (most common) but the fly in the ointment is the top strut bushing can also give the clunk in question. you cant see it, because it is on top of the strut (see 48341 in the dia below)

my DIY parts info: 48331 BUMPER, FRONT SPRING, NO.1 48331‑50070 2 $31.19
this is correct # for 1998-2000 LS

 

Yes this is for my 99'

Thanks for the quick reply and link to the Sewell site which I will bookmark now...

By purchasing part # is 4866040021 (R. Strut Bar) does that include the bushing ? Or must I also purchase # 4867440051 (STRUT BAR CUSHION) which I assume is the bushing. Do I need both or just one or the other ?

Thx

 

it comes with the bushing ... 100+ change

 

complete front strut rods are going for ~$120-130/each last i checked, with just the bushings going for ~$30-35/each.

 

you are a little off.....

I just ordered these this month from Sewell:


Item Description Status Unit Price Quantity Line Total
BAR ASSY STRUT LH
Pending $100.32 1 $100.32
BAR ASSY STRUT RH
Pending $100.32 1 $100.32
Subtotal: $200.64
Tax: $17.67
GROUND HOME DELIVERY: $13.56
Grand Total: $231.87


AND the bushings (last year) are 48674-40051 net 41.93 each.

.

 

i use carson though its been a while since i bought some, current prices are:
MSRP: $139.09 Sale Price: $115.42
before CL discount.

and i paid $34.xx (picked up/taxed) for each of my bushings last month at Westminster lexus