Date: 9 Jun 2006 20:21:24 GMT From: Dave Hinz <DaveHinznospamcop.net> Subject: Re: bad drivetrain sounds (c900)
On 09 Jun 2006 19:05:17 GMT, John B <rotten_NOSPAM_nospam.org> wrote: > > I was thinking that if it is inside the tranny, could it be something to do > with the shaft that has the gears on it and goes into the diff (I'm sure it has > a technical name that I don't know)? Output shaft but it's not that, because it'd be road speed dependant not engine speed dependant. >> Won't hurt but I think the above rules that out. Pilot bearing?!?!?! >> Actually, let's think about that. The pilot bearing, on the end of the >> clutch shaft, in the flywheel. Does that turn when you're hearing the >> noise and as you describe? > Not sure I know enough to answer that question. Agreed. Something still isn't adding up yet. We'll get there, hopefully before it announces itself to you. >> One other thing I was thinkning - can you get the noise when the car is >> just sitting still with the parking brake on? Would help diagnose it a >> bunch, and eliminate the tranny/drivetrain side of things if so, and >> reduces the options significantly. > > No, I haven't been able to do that. To hear it, the car must be (a) moving (b) > in gear, and (c) clutch engaged. But it's engine speed dependant. So then on the input side of the tranny - drive chain to input shaft? Guys, jump in at any point here... > It's not distinctly audible much over 2000 rpm, because the frequency becomes > too fast to hear individual 'clicks' or whatever. Right, I don't think the RPM matters so much as the fact that it's engine speed specific. > Can we derive anything from the frequency? It's roughly 4/5/6 per second around > 1000-1500 RPM. This means that it's maybe once per every 4 revolutions of the > engine, right? What is the ratio created by the drive chain? In other > words, how many times does the transmission turn over for each revolution of > the flywheel? Depends. Which engine/tranny/Turbo did you say you have? And why can't we hear the noise when the car is in neutral, if it's at that point? Something still isn't adding up yet.
