andyman32

Greetings good folks of Club Lexus! It has been a while since I posted.

Some time early last year I tracked through a couple of posts regarding a clunk in my suspension for my "new" '99 LS400. I checked - and ultimately replaced - all of the main culprits, although I could find no play in anything and no visual defects. To date I've replaced the following in the front end:

- Sway bar end links
- Sway bar bushinsg
- Shocks
- Strut Mounts
- Strut bar bushings
- Motor mounts (NOT FUN on these cars!)
- Steering Rack Bushings

The front suspension has stiffened up and smoothed out over bumps considerably, but still I hear this clunk that sounds like something loose.

Turns out it's in the steering column. There's some play in the shaft, around the U-joint inside the cabin. The "clunk" is somewhere up the column more towards the wheel; When I grab the column at the first (interior) U-joint, there's a CLUNK that kind of reverberates up into the dash and in the steering column. The reason I could never find anything wrong with the front end is because nothing WAS wrong with the front end. The steering column was the SOURCE of the noise, rather than simply transmitting it up into the car, as sometimes happens when you've got bad sway bar bushings, end links, ball joints, upper or lower control arm bushings, strut mounts or bushings, etc, etc.

Now, from this diagram: http://lexus.sewellparts.com/oem-cat...S400-1999.html
It looks like there is an upper and lower Shaft Snap (45201A and 45201B) and a main shaft bearing (45201A). It seems like the play may be on account of one or more of these parts wearing out. I'm not sure what else could allow this kind of up-and-down play (perpendicular to the direction of the shaft / u-joint).

Has anyone else experienced anything like this? This is DEFINITELY the nature of the clunk I've been hearing but it looks like this is a complicated device, so I can't really tear down, order parts, wait a week for the parts, then put it back together. I'm hoping to just get a good idea from where I am right now, order parts, then put it back together, and in a week or two, with the part in hand, do the full repair in a single weekend.

Thanks!
Andy

billydpowe

iTrader: (1)

I have had 3 99 LS's, and have not heard a sound like you have. if you get it fixed, be sure and post it for all to see.

Speedboat

My 2000 has exactly the same issue. I get a very sharp clunk if I go over a speedbump a little too fast, and it definitely comes from the steering column and not the suspension. It turns into a constant chattering while driving down a rough road (which I've unfortunately had to do a few times).

This is a very low mileage vehicle (80k), and the suspension has zero issues -- it's been inspected at the dealership as well as another shop. This is the only real issue I've ever really had with the car, and I sure would like to know exactly what's wrong... hopefully someone else can chime in.

PureDrifter

iTrader: (10)

that sounds exactly like the clunk you get from the strut rod bushings......

ThomasGS4

iTrader: (19)

Although this is from the 2GS section, it should pertain to the LS400 as well.

https://www.clublexus.com/forums/gs-...-movement.html

andyman32

Hi all, I thought I'd report back. Major "duh" moment, but it might be helpful for others who have a clunk that just won't go away. I've been pursuing this clunk since last January and have thrown many unnecessary parts and many Saturdays (with many cans of beer) at the problem.

Regarding the slack in the steering column, I simply loosened one of the collar nuts along the shaft and pressed out the end of the toothed shaft just inside the cabin using a screwdriver as a lever, then tightened back up. I only needed to press it out about 1/8". This firmed up the feel of the steering a bit and did eliminate the play and the associated noise I heard inside the car, but did not fix the clunk that occurred while driving.

You'll notice above that I included "shocks" in the list of parts replaced. The shocks I had purchased were super, super cheap Chinese shocks that didn't even have a brand.

To make a long story short, I'm guessing the original shocks that were on the car when I bought it were either bad, or had also been super-cheap aftermarkets the PO slapped on there before trading it in. They weren't branded Toyota. I ended up finding that a humble set of Monroe Sensa-Trac shocks have made the clunk disappear completely. The car now rides like a dream - the way a Lexus should!!!

The original noise when I bought the car last year very well may have been a compound noise from slack in a number of components I've since replaced - namely, sway bar bushings and end links, steering rack inner and outer tie rod ends, and strut bar bushings. Or, at least, I'll keep telling myself that to pretend like all the new components were worthwhile in some little way. Overall, the front end has been largely refreshed, although I have not yet replaced the upper or lower control arms or ball joints - nor do I plan to any time soon, since they still appear to be rock-solid at 75k miles!

Nevertheless, the lesson learned is, even though this kind of low-speed front-end clunk is typically blind-diagnosed as a bad strut bar bushing (specific to LS400), or more generally, lower control arms or steering tie rod ends / ball joints, cheap shocks will also do the same. Caveat emptor.

This was an expensive lesson for me, since I assumed that the new shocks had eliminated the possibility of shocks being the culprit. Shocks were the first thing I replaced last year. I even bought new through-bolts for the bottom of the shocks made of G8 steel that fit the aperture more snugly than the originals. I paid about $35 delivered for each side. The Monroe shocks can be had for $75 delivered or around $80-90 at your local auto parts store. You don't have to splurge to get a better set. I know many folks favor Bilstein or KYB over Monroe, but the point is, the Monroes work well anyway.

On we go!

billydpowe

iTrader: (1)

thanks for the update, I know all three of mine had KYB shocks, so no clunk.... very good report.

kayuwong

I just replaced my lower ball joint at 160K, it is as soft as a joystick. After replacing both sides, major differences. No more loud clunk, but I do see my inner tie rod is as weak as joystick too. I will tackle inner and outer tie rod this weekend. Will post result afterward. Replacing ball joint takes only 4 bolts only, no need to remove calipers, but do prepare yourself a big long cheater bar and 2 seperate pullers.

yoitskenn

iTrader: (4)

I have the same problem!

So is the shocks causing the thump noise in steering column?????

Did replacing shocks help anybody else?

kayuwong

First parts I changed was all-around shocks, handling was much better and firmer, but clunk noise seems to be greater by firmer shocks. You will be surprised if you just remove the outer tie rod and see how loose your inner tie rod will be. Actually all ball joints are worn out and causing mutliple clunk. Even no play by moving the wheels around but clunk noise will be there when you roll over speed bumps. If you can turn the bolt on the ball joint by hand, they are toasted and will cause clunk. My sugguestion is that jack your car up and rent a ball joint puller and tie rod puller at local parts store. Remove any upper ball joint or outer tie rod, and then turn the bolt on the ball joint. If it move like a joystick by finger, it will cause some form of clunk noise. Chances are you have multiple clunk at once. Somehow I think ball joint wear out faster than bushings. Well I think it may be various depending on locaton and climate condition. I will post after replacing inner tie rods and outer tie rods. Changing the ball joints cut down about 90% of the clunk noise for me. I am tackling the last 10%. LOL

pmesfun

Had a similar problem on my 99 Avalon, the inner tie rods were bad. The LS makes the same noise from the passenger side so I plan to replace both.

kayuwong

Just finished replacing outer and inner tie rod, no more clunk turning into drive way. Handling and feel is solid up front. Rental inner tie rod would not work on passenger side. Instead I used a plumbing jaw wrench pop it loose. You don't really need to rent that special tool. I would suggest members if you have slight pop feeling turning into driveway then change your inner tie rod. Weak inner tie rod will cause soft clunk. Just get alignment afterward.

WaveRunner

Hello Friends, I have a 1998 LS400 with 140k miles with a slight click when steering. I feel it in the steering wheel. It has a metallic sound to it. It is slight but annoying. I replaced the leaking steering rack and outer tie rods (OEM). Steering firmed a bit and is not loose like it was before but the slight click is still there. I thought the noise would be solved. I can't pin what it is but my next repair will be replacing the shocks and shock mounts. I am thinking KYB GR-2/Excel-G. I know it could be a variety of things but any input is appreciated.