Date: 10 Jun 2006 13:16:42 GMT From: Dave Hinz <DaveHinznospamcop.net> Subject: Re: bad drivetrain sounds (c900)
On 09 Jun 2006 22:01:46 GMT, John B <rotten_NOSPAM_nospam.org> wrote: > Dave, > > Ok, I got some excellent data on the drive home, which I really hope will help > rather confuse things more: Excellent. (You're an engineer and/or technician, by the way, right?) > If I drive along in 2nd gear, and then put the clutch in and shift into first, > then slowly let the clutch out, I can hear the noise, starting at a high > frequency and *slowing down* at the same time as the engine *speeds up*. So when there is a differential in speeds between the engine and gearbox, the noise changes. Right? > So, doesn't this mean that the noise is linked to the speed of the shaft in the > tranny that goes to the clutch? Yes, I think so. Looks like you're visualizing the system well which always helps. > Also, I found that if I idle the car in neutral with the clutch out, and gently > push the gear shift towards any gear, I hear a rhythmic noise very similar in > sound and frequncy to the noise in question. Not sure if this is actually the > same thing though... Well, they synchro sleeves have springs, I've never had a problem in that area. Wouldn't hurt to change your gearbox oil and check for surprises, but I'm not going to get excited about that side just yet. Is the noise there when the clutch pedal is out and you're in gear, moving forward? If so then it's not the pilot bearing; the only thing moving relative to it's surroundings then, that's at engine speed, is that shaft itself, the drive chain and sprockets, and the input shaft of the tranny and the things attached to it.
