Can Someone Tell Me What This Sound Is?

[ssilver]

Ok here is my problem, I have a manual 2004 IS300, and there is this annoying sound coming from underneath the car on drivers side.

Here are the details:

The noise only happens when the car is warm.

The noise stops when you push the clutch in just a little bit.

The faster you rev the engine the faster the sound is.

ie. if you are in neutral and you let it idle, the noise is slower, as you rev it higher the noise frequency increases

I took it into the Lexus dealership, and they said this was a known problem on the 2002, and they replaced a part of the clutch, i think they were the bearings, but this did not fix the sound.

Anyone who can help thanks -- Steve B)

[bartkat]

It does sound like it's the clutch thow out bearing. Maybe they didn't do the job right.

[dacaine]

It does sound like it's the clutch thow out bearing.  Maybe they didn't do the job right.

←

Yes, that's right. It is definitely the clutch and the throw out bearing according to my dealership in the Bay Area (Lexus of Serramonte). I have (soon to be had) a 2002 IS-300 5-Speed and Serramonte told me this was a known problem. I gave it to them to fix and they supposedly replaced the bearing, but the noise didn't go away.

I didn't take it back because it was a lease and, though the noise is definitely annoying, they said it would not affect performance or create a safety concern. Now my lease is up. I most likely will be buying a 2005 IS-300 5-Speed. I had hoped that this problem was resolved by now (3 model years later), but maybe not. Lexus isn't the best in terms of transmissions.

[randomprandom]

BUMP

Sorry to throw all these out there- but I want to get the attention of anyone that has modified the clutch

Will an aftermarket clutch get rid of this noise? or is it a transmission issue?

Thanks

Ryan

[Ericok]

It doesn't sound like the throwout bearing. The throwout bearing doesn't even begin to spin until the clutch pedal is DEPRESSSED - so the throwout bearing cannot be making a noise in neutral. It cannot be the clutch because the clutch plate is sandwiched between the flywheel and pressure plate while in neutral - it can't rattle because it has nowhere to go. It sounds like it might be the normal gear rattle experienced in a lot of manual transmissions. The gears inside are spinning while in neutral causing the rattle. When the clutch is depressed, the transmission is disengaged, the gears spin down and the rattling stops. It's just the way manual gearboxes are designed - some are noisier than others depending on how the tolerances of the gears stack up. Depending on where you live, you migt want to try a heavier transmission oil to dampen the noise. It's not just Lexus. Lots of cars have this noise. Just google BMW, for example, and you'll get hundreds of hits on manual transmission rattles. A new clutch will NOT correct the noise.

BUMP

Sorry to throw all these out there- but I want to get the attention of anyone that has modified the clutch

Will an aftermarket clutch get rid of this noise? or is it a transmission issue?

Thanks

Ryan

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[mehullica]

Known problem, it's actually the throwout bearing. The clutch fork doesn't pull back all the way and the throwout bearing slightly rides the pressure plate. I put and external return spring on the fork and the noise went away.

[Ericok]

OK, but didn't the original poster say that the noise STOPPED when he pushed in the clutch pedal? How would a "helper spring" fix his problem? Or are we discussing something different?

Known problem, it's actually the throwout bearing. The clutch fork doesn't pull back all the way and the throwout bearing slightly rides the pressure plate. I put and external return spring on the fork and the noise went away.

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[mehullica]

Because the throwout bearing is slightly contacting the pressure plate when the pedal is not pressed. Just enought contact to make some noise. When the pedel is pressed the bearing has a full load and noise goes away.

[randomprandom]

Known problem, it's actually the throwout bearing. The clutch fork doesn't pull back all the way and the throwout bearing slightly rides the pressure plate. I put and external return spring on the fork and the noise went away.

←

Thanks guys- What type of spring can I use- is it made specificaly for this application? is it for a lexus or another car? or is it a standard spring? (if so, how long, weight, etc?) Also, which fork is it attached to? Or will it be obvious to my mechanic?

I drive this thing hard, and I want to continue doing that. This noise is not acceptable! I was considering dropping a supra getrag 6-speed in here if it really was a Lexus transmission issue.

I will try the spring, and if that doesn't work (or does, but not completely- I will try the BG synchroshift fluid for transmission rattling.

Thanks for the help guys!

[Ericok]

Well, if Mehullica is right, just about any spring strong enough to hold the clutch fork back and take up the slack would be ok - just keep in mind that it will add to the pedal pressure. If this is really a design problem and not some kind of adjustment issue then Lexus should come out with a redesigned shift fork or hydraulic cylinder to keep this from happening. Note that Supra owners with the Getrag unit complain about gear rattle and that car has a dual mass flywheel to minimize the problem. Corvette owners also complain about gear rattle with Getrag units (although obviously they're not the same unit as the Supra).

Known problem, it's actually the throwout bearing. The clutch fork doesn't pull back all the way and the throwout bearing slightly rides the pressure plate. I put and external return spring on the fork and the noise went away.

←

Thanks guys- What type of spring can I use- is it made specificaly for this application? is it for a lexus or another car? or is it a standard spring? (if so, how long, weight, etc?) Also, which fork is it attached to? Or will it be obvious to my mechanic?

I drive this thing hard, and I want to continue doing that. This noise is not acceptable! I was considering dropping a supra getrag 6-speed in here if it really was a Lexus transmission issue.

I will try the spring, and if that doesn't work (or does, but not completely- I will try the BG synchroshift fluid for transmission rattling.

Thanks for the help guys!

←

[rmwjr]

New guy here with a clutch rattle in neutral...can anyone tell me more abut this spring? Is there another fix that works?

The only difference in what I see here any my case is I have to push the clutch in about 1/2 way to prevent the sound, others say they jsut tap it to kill the sound? (2002 IS300 MT, 68k miles)

Thanks in advance!