Dale Gribble

I've been hearing a whining noise (sounds like some kind of gear noise) on deceleration below 3000RPM.

The noise is not present under any kind of load at all (no matter how light), and is not present above 3000RPM. It also dissapears when the clutch is in.

I don't believe it's the transmission because the synchro's seem fine, car gets into every gear smoothly without grinding or issue.

Off the top of my head i'm thinking it might be:
- Rear differential (car has the factory LSD option that came with the 99's).
- Clutch/flywheel or a bearing related to them? I'm pretty sure the car's had a busted clutch spring since...well...prolly since it rolled off the assembly line.

Any thoughts on the matter? Car still drives flawlessly overall so i'm not particularily concerned...diff's arn't too pricey. A transmission issue though would really hurt the wallet right now =(

Pac996

Gearing will make noise no matter what. Altering weights of oil change change or make noises disappear. Even if the noise is from a slight play in gearing it doesn't mean its a problem that needs attention right now.

Shark Attack

how many miles. Did you have it serviced. I think they changed my gear oil at 90K The below 3K rpm doesnt make any sence. well I guess it can.. The input shaft is always spinning at engine RPM. IM thinking input shaft bearing. To me that would make most sence. Becasue it goes away when you push in the clutch. Thus taking the load off the input shaft.

But I have never had a tranny open. Just looking at the WSM

Dale Gribble

75,000kms so not sure what that is in miles...60K Miles maybe? I change the gear oil every 3 seasons or 15,000. whichever comes first.

What's a WSM?

Pac996

Maybe work service manual for WSM.

You could ake a look under the car to inspect the rubber boots on the rear axles. The cvc boots if they have cracks or are ripped open can cause degrading of the lube back here giving rise to noises. Its an easy check especially if you lift the car.

Dale Gribble

This thread came up in a search I was doing and coincidentally enough we just solved the problem so i figured I'd update incase anyone else had this problem.

It was the shaft bearing. The porsche part (thru porsche canada at least) is stupid expensive for what it is, you might want to consider having your mechanic go to a bearing place and putting in a non-porsche part of same design.