I know that when the clutch is engauged you are supposed to hear a slight whirring noise from the transmission as the input shaft is spinning inside. I've observed the sound in both my Si and WRX, only in the S14 it seems much louder. The sound goes away when the clutch is depressed/disengauged.

Also when I change gears at RPMs above 4k in 1st and 2nd gear I can hear a strange vibration sound come from the clutch area and I can feel it in the clutch pedal. I used to think that it was the exhaust as the car came with a fart can HKS Hi-power cat back, but now I'm affraid that I may have a wobbly input shaft and/or a bearing going bad inside the transmission.

Is what I describe symptomatic of bad internal transmission bearings?

Some one please help the nissan noob. Thanks!

Not that I have noticed. The slight whirring sound only occurs in neutral. Every MT car I've had does this, only the 240 seems louder. The vibration sound/feeling doesn't seem to occur in 3rd gear on up, but I usually don't make it much past 4k in either of those gears. I've discovered that I have a few exhaust leaks as well when I was under the car this weekend, so I may be hearing that as well. Another thing I noticed when I've been driving around with the windows down is that when I engage the clutch to shift I can hear a slight squeak/squeal which would support doubled340's theory of a bad TOB.

The car runs and drives fine, so I guess I'll just keep driving it until it gives up the ghost. I have a feeling its my TO bearing though... let's hope anyways, I don't feel like buying and installing another transmission before I go RB next year.

Thanks for the help!

Modified by cation at 5:17 PM 5/18/2008

If or when it gets worse, it'll only be like $150 for a clutch kit and flywheel resurface if you can do the labor yourself.