The Old Clunking Noise from the front !

[stevechumo]

I've replaced all the front upper & lower control arms bushings. I checked the ball joints and they're still good. The bump stops that slide on the shock rods are good, too. The lowered springs & shocks are just new. However, I still have the clunking noise from the left front over dips & bumps. When it happened, I felt like the left front suspension was cracking. Also, I felt like the left front leans down much more when I make the right turn. Does anyone know what else caused this?

Any idea is greatly appreciated.

 

[Lextreme II]

This is your problem http://www.lextreme.com/strutbar.html

 

[stevechumo]

Thanks, Lextreme. I'd like to ask just 2 more questions. Is it possible just to replace the left strut bar bushing only? Is it necessary to do the alignment after its replacement? Thanks again.

 

[Lextreme II]

1. yes you can but why? You should do both and its pretty easy and u can do it with few basic tools

2. No you have to re-aligment you aligment again if you mark you nuts and position, but its good idea if you do. Best of luck.. and take some pics of the process.... and tell us about it.

 

[stevechumo]

1. yes you can but why? You should do both and its pretty easy and u can do it with few basic tools

2. No you have to re-aligment you aligment again if you mark you nuts and position, but its good idea if you do. Best of luck.. and take some pics of the process.... and tell us about it.

I would love to post some pics about the process of this. However, as I went to a Lexus Dealer and ordered for the strut bar bushing, the technician told me there is not any strut bar bushing on my SC 400. There're only the lower arms & upper arms connected to the knuckles on my car, plus the sway bars. And inside the knuckles, there isn't any bushing besides the bearing and the speed sensor. He told me the clunking noise could be from the strut top mount that mounts the strut assembly to the chassis. But I think the strut top mount looks pretty solid with no bushing in it. As I looked suspiciously, he even gave me the pic diagrams with all the components on them. And I didn't see any strut bar bushings on them. So now, I don't know what to do, and maybe I'll go for a strut top mount and see how it'll turn out.

 

[Lextreme II]

Its cheaper and easier to replace what i suggested. I am 95% sure that is the problem.

 

[stevechumo]

Hello Lextreme,
I tried to upload the pic of the knuckle components on my car, but I couldn't because it kept saying the file is too large, although I've already reduced the image down to 89 KB. Is there anyway that I can upload this pic? I thought under 100 KB is ok. Thanks.

 

[jibby]

Hey Steve It Is John, Try Searching The Junkyards For Two Supra Front Control Arms Change Out The Bushings Install On Your Sc And Watch The Handling And Reponsiveness In Your Stearing And Ride Change Dramatically, I Would Bet You Would Not Have That Noise Clunk Problem Anymore Either. That Is What I Am Doing To My Sc400. Monday I Will Try To Find A Set, Already Have Nascar Bushings To Install In Them.

 

[stevechumo]

Hey Steve It Is John, Try Searching The Junkyards For Two Supra Front Control Arms Change Out The Bushings Install On Your Sc And Watch The Handling And Reponsiveness In Your Stearing And Ride Change Dramatically, I Would Bet You Would Not Have That Noise Clunk Problem Anymore Either. That Is What I Am Doing To My Sc400. Monday I Will Try To Find A Set, Already Have Nascar Bushings To Install In Them.

Uhmm!!! You might be right but it took me almost 2 days, 1.5 days to be exact, to replace them with the Daizens. The ride was totally improved with all the smoothness on the steering wheel, but the clunking noise seemed to be something that is cracking under there. Therefore, I think it might be something else, and not from the control arm bushings.

 

[jibby]

Did you check the shocks? bolts tight shock functions normally? Does the noise happen when you turn or just when you hit bumbs. I am removing my front control arms today, that is usually where all stability and noise issues come from. Your bushings are not loose are they? Good luck with that noise, I would love to help you but need more info. Steve.

 

[Lextreme II]

You can upload pictures via this link http://www.lextreme.com/forums/showthread.php?t=1068

 

[stevechumo]

Did you check the shocks? bolts tight shock functions normally? Does the noise happen when you turn or just when you hit bumbs. I am removing my front control arms today, that is usually where all stability and noise issues come from. Your bushings are not loose are they? Good luck with that noise, I would love to help you but need more info. Steve.

All the shock assemblys and bushings are good. I torqued all the bolts as factory specs. The noise only causes over dips usually. That's why I'm really annoyed when that happens. If I'm positive of what it is, I'll fix it immediately. However, I'm afraid that I'll be spending more $$ without fixing the problem. As you know, SC parts are so expensive ridiculously.

 

[Lextreme II]

As stated previous. U should highly consider the strut bar cushion. See the picture below. Strut Bar Cushion in located lower left of the diagram below.


Here is another picture of the strut bar cushion:

 

[stevechumo]

Thanks, Lextrem. Here's the link to the pic of the knuckle components on my SC. First link: http://lextreme.com/members/SC_knuckle.JPG. Second link: http://lextreme.com/members/Suspension2.JPG. And the third link is with the top strut mount that the technician at Lexus recommended me to change. http://lextreme.com/members/Suspension1.JPG. Could you please look at them and tell me which one is the strut bar bushing? They don't really look like yours on the LS400.

 

[Lextreme II]

Sorry Steve, the SC400 does have different suspension. I looked the SC400 suspension setup and its totally different. From that said, SC400 doesnt have Struct bar cushion....

 

[jibby]

That noise is coming probably from the upper or lower control arm or shock. Start with the shocks, you may have a bad one, switch shocks from right to left side to test. Then that will elliminate the shocks if the noise remains with no change, then go for the upper control arm, use a jack to raise and lower the suspension with the tire off, then look where the noise is coming from. Repeat with lower and this should solve your problem, that is what I would do. You will need to jacks to perform the tests.

 

[stevechumo]

Thanks to Lextreme and John for your consideration on my problem. I'll try the method as John said, but I don't know if I can do that fast and strong as when the car goes over dips. However, it's a good idea and worth a shot.