SaberD

going to replace the throwout bearing when i do the clutch. just wondering if anyone still got the infamous rattle noise that is supposed to be "normal" even after you replaced the bearing.

what can be done to prevent the noise?

Thanks!

primo_c5

Bump

Eric D

If you are talking about the rattle noise that all C5 & C6 manual transmission cars have at launch, it’s not the throw-out bearing. So, no, changing the bearing will not stop the noise. Nothing short of a dual mass flywheel will stop it. Sorry...

SaberD

wow thats the first time ive heard that. up until now all i heard was that the TO bearing caused the noise. looks like ill just have to deal with it.

Eric D

It's in your car's manual and in the video that came with it too. If you really want to hear the noise, put the car in neutral, let the clutch out, and then turn the ignition off. It's not recommended to do this often though. In fact the manual tells you not to.

SaberD

so are you going to let me in on the big secret as to what the noise actually comes from?

Eric D

I don’t think it’s a big secret; the noise comes from the propshaft going through its resonant point. I don’t remember the exact frequency, but it is something like 10Hz or lower. The torsional input of the engine cylinder pulses during shutdown or launch cause the propshaft to excite until the propshaft rpm is high enough, or stops turning during shutdown.

bumble-z

Bought my 03 Z new.
It's made the t/o bearing noise from day one.

m6 c5

Just wondering why is it not recommended to shut the car off while it is in neutral?

thatonedude1

I had the same noise on my 96 Z28 with the 6 spd manual. Never got better or worse over 5 years. Believe Eric is totally correct. It's a harmonic resonance. I think it's somewhere in the clutch assembly. I used to notice it at about 1500 RPM, which would be about 25 hz. 25 hz would be typical for rather flexible plates. I don't think it's anything to worry about since the car does not dwell there, but rather spins thru this frequency quickly.

Acrespo1986

i think he's referring to letting the clutch out ,being recommended to not do it often

Eric D

The issue is when the clutch is out in neutral, the propshaft is spinning. This is what needs to be avoided. It's hard on the propshaft assembly. It can cause premature failure of the flex couplings.

m6 c5

Im guessing that the wear would be from the resonating, I havent really noticed the rattle in a long time to be honest but Im going to make sure I keep the clutch in when I shut if off, dont think that I do it anyways but Ill pay attention to it now.

C5kid

Carbon fiber drive shaft fixes that noise

bumble-z

$$$ ouch! $$$

Eric D

You can't fix what's not broke. Carbon fiber only changes the frequency of the resonant point. Maybe to a less desirable point.

C5kid

I have no rattle on mine w/ the CF driveshaft. Probally did change the freq. but its at a point that you don't hear.

Just wonder if other CF driveshaft users took notice to the rattle disappering.

Nightstalker346

My vette 02 m6.


I put it in neutral and let out on the clutch it makes a wired ticking sound but as i push in the clutch it goes away any problems

civi

I want to make sure I get this right

At a traffic light that I know is going to take about 2 mins to get back to me for a green light, I should not put it in neutral and take my foot off the clutch ? Foot on brake of course

OR

just avoid doing this while turning it off? Sorry, I'm confused

73Corvette

The noise is called the Infamous Neutral Rattle.... avoid neutral and avoid the noise.
I don't know why anyone puts their car in neutral at a light anyway?

Car in gear, clutch depressed for shutdown...

About the only time my car sees neutral is when I'm blowing by it to grab another gear... woohoo