91ls400 Posted March 2, 2005 Share Posted March 2, 2005 Ok guys i have had this crunching and groaning noise since I got the car a little over a year ago. Its a 91 LS400. I've got a little curb at the end of my drive and every day I drive over it and I hear this awful noise. I know its got something to do with the front wheels. I have read all kinds of posts that say this or that, but I'm really not sure what it is! The noise used to seem to come from just the right side, but over the last year it has started to come from both sides and its getting louder. I have also noticed that when applying the brakes moderately hard they also make a groaning noise, is this related in anyway? I'm not what you would call the best mechanic, but I'm always looking for a project! Quote Link to comment Share on other sites More sharing options...
Econ Posted March 2, 2005 Share Posted March 2, 2005 My bet would be upper control arm bushings are shot. And the groaning in the brakes might be the control arm, or it might be your rotors. Of course, I'm not a mechanic. I'm hoping others will post up as well. Quote Link to comment Share on other sites More sharing options...
90LS400Lexus Posted March 3, 2005 Share Posted March 3, 2005 My 1990 LS did not have any creaks or crunching from the front suspension, but it did have a terribly annoying clunking sound when I would hit bumps. Quote Link to comment Share on other sites More sharing options...
Wilfred Posted March 3, 2005 Share Posted March 3, 2005 I heard creaking too this week when turning the wheels at very low speed (ie in a carpark). I probably have the same problem but i have airsuspension. What should I do? Should i replace anything? btw its a 1990 LS400 Thankyou in advance. Quote Link to comment Share on other sites More sharing options...
Econ Posted March 3, 2005 Share Posted March 3, 2005 Ok, since there aren't any other opinions, I'll throw out a quick diagnostic you can do: Lift one side of the front of the car off the ground - remember that you need to turn your air suspension height control to "off" before you do this. (If you only have one creaking side, then make sure it's that side) Raise the car until the wheel is about an inch or two off the ground - you want the suspension fully extended downward. Grab the top of the wheel and push/pull firmly back and forth a few times. If you feel any shift (and I mean -any- shift), hear any clunking, etc., then your upper control arm likely needs replacing. There's also a possiblity that this could be your wheel bearings. To test those, while the wheel is at full droop (just like the above test) grab the wheel on each side and rock it back and forth firmly. Shifting (make sure the steering wheel is locked) or clunking is a sign that your wheel bearings might be going. If this doesn't help, let me know. Maybe there's another way to attack this to identify the source of the offending noise. Quote Link to comment Share on other sites More sharing options...
maxed_out Posted March 3, 2005 Share Posted March 3, 2005 I'll throw in my 2 cents...sway bar bushings if its clunky. bearings if its groaning. could be brake pads/ rotor related and/or caliper pins not greased. I guess we need more specific info if you want it nailed. Quote Link to comment Share on other sites More sharing options...
91ls400 Posted March 4, 2005 Author Share Posted March 4, 2005 I dont really know how to describe it, but today I had to hit the brakes pretty hard some guy just ignored a stop sign, you know the type. I hit the brakes hard enough to slow really fast but not enough to make them lock up. The brakes were nice and firm until I almost stopped then the car started to shudder, but it wasnt ABS. Could that be related in anyway? It def was from the front of the car. Quote Link to comment Share on other sites More sharing options...
91ls400 Posted March 4, 2005 Author Share Posted March 4, 2005 Also its not the brake system, I had it checked less than a month ago and it checked out alright. Quote Link to comment Share on other sites More sharing options...
Black Lex Posted March 4, 2005 Share Posted March 4, 2005 Also its not the brake system, I had it checked less than a month ago and it checked out alright. ← <_< You might want to try spraying silicone spray on the antiroll bar bushing I had some clunking up front over bumps and that did the trick for me Quote Link to comment Share on other sites More sharing options...
Wilfred Posted March 4, 2005 Share Posted March 4, 2005 Also its not the brake system, I had it checked less than a month ago and it checked out alright. ← <_< You might want to try spraying silicone spray on the antiroll bar bushing I had some clunking up front over bumps and that did the trick for me ← Wheres the antiroll bar busing? Where do I spray i might try this too Quote Link to comment Share on other sites More sharing options...
Econ Posted March 4, 2005 Share Posted March 4, 2005 I dont really know how to describe it, but today I had to hit the brakes pretty hard some guy just ignored a stop sign, you know the type. I hit the brakes hard enough to slow really fast but not enough to make them lock up. The brakes were nice and firm until I almost stopped then the car started to shudder, but it wasnt ABS. Could that be related in anyway? It def was from the front of the car. ← You know, if your car was shuddering at slow speeds and you're confident that the brakes are ok, it might just be your strut bar bushing. (Also called radial-arm bushing) It's the bushing that cushions the front-back radial motion of the steering knuckle (or caster). My theory is that the harder braking causes the wheel to move backwards slightly, which pushes the radial arm down on the bushing. Since deceleration is non-linear, would it be possible that the radial arm is pushed downward even harder the slower you go (to the point that you stop, when it returns to it's normal position) and that a worn bushing could result in the radial arm clunking against the bottom of the bushing bracket? The repeated clunking could be the arm meeting resistance and bouncing off of the metal and then being forced back down on it again. The pirate think's it's a good idea to check your bushings. Quote Link to comment Share on other sites More sharing options...
Black Lex Posted March 7, 2005 Share Posted March 7, 2005 Also its not the brake system, I had it checked less than a month ago and it checked out alright. ← <_< You might want to try spraying silicone spray on the antiroll bar bushing I had some clunking up front over bumps and that did the trick for me ← Wheres the antiroll bar busing? Where do I spray i might try this too ← there in about a foot from the inside of the front wheels . antiroll bar and swaybar are the same thing. It's easier to get at if you take the wheels off first . then just spray around the rubber bushing . on top if you can so that gravity can work it in through the small gaps on top of the bushing. This is just a temperary fix that should last months . If this is the problem you have you will probably need to replace bushings in the future. Quote Link to comment Share on other sites More sharing options...
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