Rattle / clunk in gs300 front end
#1
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Hi all,
i bought a beautiful 2000 GS300 a year ago, 200k, in beautiful condition, love this car! it needed lower ball joints, which i replaced with OEM.
at some point it has developed a really annoying rattle / clunk in the front. hard to replicate for a mechanic, will try and describe here:
90% of the time it does not exist, car sounds fine on highway, over speed bumps, and on uneven surfaces. but imagine a series of potholes that are only 1 cm deep, patched poorly. if i drive over that, especially going downhill, especially under light braking, there's a loud rattle from the front right. it's not a light tinny rattle as though it were thin metal or plastic, it's a loud solid knock / rattle clunk that sounds like something heavy or solid. and it's a fast rattle. say five to ten clunks per second at highway speed. so to this amateur, it seems to be related to the movement of the wheel, not movement of the body / chassis.
one mechanic put it on a hoist and used a heavy screwdriver / vice grips to demonstrate a small bit of movement in the right UPPER ball joint, and he said that would cause the noise. he said that amount of movement was "not dangerous, but a sign that it needs replacing, and a likely cause of the noise". likely, but not certain. another mechanic said "I've seen a couple of GS300s with that kind of noise, and it turned out to be the shock absorber MOUNT ASSEMBLY (not the absorber itself). I'm not a DIY mechanic, so whichever it is, I pay mechanic. i can't really afford BOTH repairs, so I guess i have to pick one and take a 50/50 chance that my chosen repair will fix the noise. but ... any of you folk have any advice that steers me to one solution over the other?
such a beautiful car in every way, the noise is killing me!
and, in either case, how important is OEM vs aftermarket? i live in Australia.
cheers,
gary
i bought a beautiful 2000 GS300 a year ago, 200k, in beautiful condition, love this car! it needed lower ball joints, which i replaced with OEM.
at some point it has developed a really annoying rattle / clunk in the front. hard to replicate for a mechanic, will try and describe here:
90% of the time it does not exist, car sounds fine on highway, over speed bumps, and on uneven surfaces. but imagine a series of potholes that are only 1 cm deep, patched poorly. if i drive over that, especially going downhill, especially under light braking, there's a loud rattle from the front right. it's not a light tinny rattle as though it were thin metal or plastic, it's a loud solid knock / rattle clunk that sounds like something heavy or solid. and it's a fast rattle. say five to ten clunks per second at highway speed. so to this amateur, it seems to be related to the movement of the wheel, not movement of the body / chassis.
one mechanic put it on a hoist and used a heavy screwdriver / vice grips to demonstrate a small bit of movement in the right UPPER ball joint, and he said that would cause the noise. he said that amount of movement was "not dangerous, but a sign that it needs replacing, and a likely cause of the noise". likely, but not certain. another mechanic said "I've seen a couple of GS300s with that kind of noise, and it turned out to be the shock absorber MOUNT ASSEMBLY (not the absorber itself). I'm not a DIY mechanic, so whichever it is, I pay mechanic. i can't really afford BOTH repairs, so I guess i have to pick one and take a 50/50 chance that my chosen repair will fix the noise. but ... any of you folk have any advice that steers me to one solution over the other?
such a beautiful car in every way, the noise is killing me!
and, in either case, how important is OEM vs aftermarket? i live in Australia.
cheers,
gary
#2
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The most common rattle I battle up front is the sway bar. Check to make sure it is tightly secured. With that said, someone out here might get lucky and guess your rattle, but truthfully we're all just guessing.
If the sway bar isn't it, I experienced a rattle going over light bumps recently which took me a while to diagnose. It turned out to be the front upper control arm. It was rattling where it mounts to the body - the bushing was evidently worn. I was able to replicate this by lifting the wheel off the ground, and striking the tire at the 12-oclock position with my palm with a good bit of force. I would hear and the feel the rattle from this. To confirm, I put my other hand on the arm and held tension in the opposite direction and the rattle went away. Further, I could feel the vibration of the rattle in the upper control arm when it occurred.
There are of course a number of components up front that would rattle. If you used genuine lexus/toyota lower balljoints, I wouldn't suspect those. If you used aftermarket, some are junk and it isn't out of the question they could be failing again.
If the sway bar isn't it, I experienced a rattle going over light bumps recently which took me a while to diagnose. It turned out to be the front upper control arm. It was rattling where it mounts to the body - the bushing was evidently worn. I was able to replicate this by lifting the wheel off the ground, and striking the tire at the 12-oclock position with my palm with a good bit of force. I would hear and the feel the rattle from this. To confirm, I put my other hand on the arm and held tension in the opposite direction and the rattle went away. Further, I could feel the vibration of the rattle in the upper control arm when it occurred.
There are of course a number of components up front that would rattle. If you used genuine lexus/toyota lower balljoints, I wouldn't suspect those. If you used aftermarket, some are junk and it isn't out of the question they could be failing again.
#3
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For me, it was upper arm ball joint.
Just replaced it (driver's side on mine, but I'll do both sides anyway) and all that rattling sound is gone.
Eventually I found a way to reproduce them. You don't need a lift or any tools. You can do it right in the parking lot.
Grasp the top rear of the front wheel firmly and shake it well towards you several times. As if rocking a wheel like a boat![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
If you do it correctly, you will apply the correct force to the upper ball joint and it will immediately produce "clunk-clunk" sound.
To replace the upper arm with a ball joint, the mechanic will have to remove the strut assembly so that the upper mount can be very well inspected from both sides.
Mine one had no problem with the upper mount, but I have replaced the shock absorber, upper mount, dust boot / bump stop and sway bar link.
Just because I was already there and didn't want to do it again anytime soon.
Used OEM shock absorber, upper mount, rubber dust boot / bump stop and sway bar link.
But I used aftermarket upper arm Mevotech. Pretty decent quality seems to me, but I can't say much right now because only a few hundred miles have passed since then. Time will tell
Just replaced it (driver's side on mine, but I'll do both sides anyway) and all that rattling sound is gone.
Eventually I found a way to reproduce them. You don't need a lift or any tools. You can do it right in the parking lot.
Grasp the top rear of the front wheel firmly and shake it well towards you several times. As if rocking a wheel like a boat
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
If you do it correctly, you will apply the correct force to the upper ball joint and it will immediately produce "clunk-clunk" sound.
To replace the upper arm with a ball joint, the mechanic will have to remove the strut assembly so that the upper mount can be very well inspected from both sides.
Mine one had no problem with the upper mount, but I have replaced the shock absorber, upper mount, dust boot / bump stop and sway bar link.
Just because I was already there and didn't want to do it again anytime soon.
Used OEM shock absorber, upper mount, rubber dust boot / bump stop and sway bar link.
But I used aftermarket upper arm Mevotech. Pretty decent quality seems to me, but I can't say much right now because only a few hundred miles have passed since then. Time will tell
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
Last edited by DundukovEM; 06-24-21 at 08:54 PM.
#7
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Hi everyone - to bring this thread to a close, today the rattle was fixed with replacement of the single upper (driver side) ball joint / control arm. Car feels and sounds like a quality, tight, luxury ride again! Thanks for input.
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