Loud Clunk! Ls400

[MORGAN]

Hi guys i recently bought a 1997 ls400 with 75000 miles, the car has a loud clunk in the front right side of the car, it seems to be coming from the suspension but whe have checked springs, struts, strut bar bushings, we changed the lower ball joint, stabilizer bar bushings are ok, anyone have an idea what this could be? the noise is heard when going on uneven surfaces, we also checked brakes and pads, door and hood hinges, took it to an aligment shop and they said everything in the suspension seemed fine, no cracks in the underbody either. Please help me i love the car but te noise is driving me nuts!

[95LS400Bob]

We found the clunking in our front end (right side) by just rolling forward in gear at idle and hitting the brakes hard. We noticed the front wheel (in relation to staying centered in the fenderwells) would move forward with a loud "pop". The lower strut arm bushings looked o.k. But when I actually pulled the strut bar out..the bushing had torn inside and that allowed the strut arm to "slide" when loaded and hit the strut bolt support.

So see if you see any wheel for or aft movement by watching the wheel while someone hits the brakes hard.

This soft Lexus rubber used in bushings and motor mounts also tends to "cover itself up" and look like molded the way it should be...while it is really torn loose.

The left side was also bad...but it didn't make noise. But that wheel moved. Strange thing is..the left side bushing was far worse than the right side...but never made the "pop" sound.

Remember that the Lexus suspension design counts on the that lower strut bar to keep the entire wheel assembly in place. Lot to ask out of a rubber bushing.

[99lsguy]

Bob is correct!!!

Those strut rod bushings do wear and "clunk" metal to metal.........

[LWR]

Ours,which is the same year model, had that noise too.Turned out to be radius arm bushes and engine mounts.

I was a bit surprised at only 60,000 KM's.

[90LS400Lexus]

My 1990 LS with 233K does the exact same thing. I have to go with the windows down, since my A/C is broken, so it is not as noticable, in addition- I leave my radio volume up. It was very annoying at first, but I have become immune to it.

[wmOH]

I just replaced the F&R stablizer bushings. That 'clunk' I used to hear going over speed bumps at low speed is gone. The old bushings did not look worn, but they were harder than the new ones. The design of the fronts are slightly different from the originals, the cut is on the side and not on the top. Before anyone considers replacing struts or any other suspension part to get rid of the 'clunk', try this inexpensive and quick fix.

[RCRFAN3]

I have a 98 LS 400 that is doing the same thing I'm going to replace the strut rods on both sides total cost of parts $ 180.00

[mickg]

I have a 98 LS 400 that is doing the same thing I'm going to replace the strut rods on both sides total cost of parts $ 180.00

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Morgan:

My '94 makes a similar noise, only when the mornings are cold though. It comes from the stabilizer bar bushings, even though they are in good condition.

A shot with silicone sprayat the bar/bushing interface on both sides works wonders. I need to repeat about every 3 months.

Mick

[lex4me]

I installed the Daizen bushings on my 91LS when I replaced all of the rest of the components on my front end and wasn't pleased, FWIW. Although the lower bushings worked fine, I noted that the upper bushings failed to take into consideration the interesting fact that new OEM control arms (which I installed since my upper ball joints were worn) had a substantially thinner cross section than the original OEM control arms. As a result, although everything looked good, you could move the control arm front to back pretty easily (royally !Removed! up your caster settings and wreaking havoc on tire wear) with these bushings installed. I migrated back to the original OEM upper control arm bushings (so glad I bought that press...) and the problem is gone.

I have yet to contact TM Engineering (the bushing manufacturer) on this issue, but have plans to.

Also, FWIW, I learned an interesting trick from a mechanic friend of mine. I was very, very concerned about damaging the upper ball joint boot on my brand new upper control arms when I went to put the OEM bushings back in as a result of using a conventional puller to remove the upper ball joint from the knuckle. He said that his shop never uses a puller to remove upper ball joints, but rather takes a small sledge hammer and hits the knuckle at the point where the upper ball joint goes through. This, he says, sets up a vibration in the metal that pops it loose. It didn't work the first time I hit it, but I gave it a slightly bigger hit and out it came. Life is good. :D

[99lsguy]

I installed the Daizen bushings on my 91LS when I replaced all of the rest of the components on my front end and wasn't pleased, FWIW.  Although the lower bushings worked fine, I noted that the upper bushings failed to take into consideration the interesting fact that new OEM control arms (which I installed since my upper ball joints were worn) had a substantially thinner cross section than the original OEM control arms.  As a result, although everything looked good, you could move the control arm front to back pretty easily (royally !Removed! up your caster settings and wreaking havoc on tire wear) with these bushings installed.  I migrated back to the original OEM upper control arm bushings (so glad I bought that press...) and the problem is gone.

I have yet to contact TM Engineering (the bushing manufacturer) on this issue, but have plans to.

Also, FWIW, I learned an interesting trick from a mechanic friend of mine.  I was very, very concerned about damaging the upper ball joint boot on my brand new upper control arms when I went to put the OEM bushings back in as a result of using a conventional puller to remove the upper ball joint from the knuckle.  He said that his shop never uses a puller to remove upper ball joints, but rather takes a small sledge hammer and hits the knuckle at the point where the upper ball joint goes through.  This, he says, sets up a vibration in the metal that pops it loose.  It didn't work the first time I hit it, but I gave it a slightly bigger hit and out it came.  Life is good.  :D

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Thanks for this info Lex..........

[dpusa55]

Guys! THese clunks do NOT come from suspension! Replace front wheel hubs. Almost guaranteed fix for LS430.

[billydpowell]

Quote

 

this post is also 12 years old..

[Exhaustgases]

On Friday, December 3, 2004 at 9:31 AM, lex4me said:

I installed the Daizen bushings on my 91LS when I replaced all of the rest of the components on my front end and wasn't pleased, FWIW. Although the lower bushings worked fine, I noted that the upper bushings failed to take into consideration the interesting fact that new OEM control arms (which I installed since my upper ball joints were worn) had a substantially thinner cross section than the original OEM control arms. As a result, although everything looked good, you could move the control arm front to back pretty easily (royally !Removed! up your caster settings and wreaking havoc on tire wear) with these bushings installed. I migrated back to the original OEM upper control arm bushings (so glad I bought that press...) and the problem is gone.

I have yet to contact TM Engineering (the bushing manufacturer) on this issue, but have plans to.

Also, FWIW, I learned an interesting trick from a mechanic friend of mine. I was very, very concerned about damaging the upper ball joint boot on my brand new upper control arms when I went to put the OEM bushings back in as a result of using a conventional puller to remove the upper ball joint from the knuckle. He said that his shop never uses a puller to remove upper ball joints, but rather takes a small sledge hammer and hits the knuckle at the point where the upper ball joint goes through. This, he says, sets up a vibration in the metal that pops it loose. It didn't work the first time I hit it, but I gave it a slightly bigger hit and out it came. Life is good. :D

Yeah old post.... I know. But since they are here and people still read them.....

Any way the hammer removal method does not set up a vibration, as you can vibrate the heck out of it with an air hammer. What the hammer does is distort the taper a small amount and then it will release the male taper.

[Micah.Berry]

Hammering helps free frozen-with-rust parts.  I have just bought new pads, rotors, lower ball joints, new upper control arms, new outer tie rod ends, new strut assemblies, and new lower strut bars.  For the parts that are coming out, I have no problem hammering, though I will start with a rubber hammer.

[Exhaustgases]

A rubber hammer will not release it since it will not distort the steel. I have used the hammer method against my better judgment on a Mercedes and it took way more than a few light love taps, we are talking major impact stress on everything. And that was with a puller applied at the same time.

[Micah.Berry]

This is what I was referring to as an example.  To your point, rubber won't distort steel.