Possible layshaft rumble?

[Vic Rattlehead]

Lol, feels like things never end with this car.

With engine running and the car in neutral with the clutch out (pedal up) there's like a rumble or low pitched grinding noise like something is rotating. Engage clutch and the noise is gone. release an it's quiet up until around where you expect the clutch to bite. With my head out of the car it sounds like its from the rear.

I'm pretty fuzzy on gearboxes but i'm thinking layshaft or whatever componant that wears around the layshaft is dying. And I thought I read somewhere that the 944 suffers from layshaft rumble. Would like peoples opinions.

I've found a transmission on ebay for £250. Apparant good condition, and would do the swap myself unless a shop would do a rebuild for cheaper.

Also, whilst I'm in there with the transmission dropped, how hard is it to change the clutch? I've read various stories about it and vowed it'd be a shop job if the clutch ever died.

[Razorback1980]

It could be a bearing in the transmission, however I am suspecting it's what I always called the throw out bearing. That's the bearing that rides on the pressure plate to disengage the clutch. Sometimes when they get a little older they make a noise when the clutch is out as they are not under load. When you push the clutch in, the bearing is pressed against the pressure plate and therefore under load and the noise stops. I am thinking the best way to tell is to determine if the noise is actually coming from the back of the car or just past the back of the motor. Put it up on stands and let it idle in nuetral with the clutch out and check out where the noise is coming from. There might be a better diagnostic procedure, I just can't think of it at the moment...maybe someone else has a better procedure.

[Vic Rattlehead]

Thanks man. Coincidently the release bearing on my dads car bit the big one and before changing out it made a squealing sound but only when the clutch was depressed. Clutch up and it was quiet. It sounded like it was screaming when you went to change gear

Although we maybe reffering to different bearings lol. But it was the bearing that sits inside the bell housing. And would be directly behind the clutch when installed. As I say transmissions arent my strongest point.

But axle stands sound good. It does sound like its from the rear. I'd honestly rather it be the tranny than the clutch lol.

[Razorback1980]

When throw out bearings are actually a bad bearing that is causing the problem it will do what you described in your dad's case. We are in fact referring to the same bearing. In your case where the bearing is making a noise when the clutch is at the top, then it's because there is a gap in there and the bearing is moving around not because the bearing itself is bad. Most of the time it's not the bearing causing the noise in your case, it's a weakened pressure plate. Most people just continue to run them for a very long time when they only make noise when the clutch is at the top in neutral because there really isn't anything that is broken. If the pressure plate is indeed a little weaker than when new, the only thing you feel is the clutch will slip easier under power. Of course in drag racing, that's bad but under normal driving, it's nothing to really worry about. Hope this is what it is more than the transmission because if it is, I would suggest that you just keep driving it until the clutch needs to be changed.

[Vic Rattlehead]

Cool. Thanks for the advice Razor.