2006 Boxster differential noise---gear whine

[kamran66]

Hi folks, I just picked a 2006 Boxster, car looks and runs great except for a gear whine in 4th and 5th, it gets very noticeable at around 2700 to 3000 RPM. When I'm cruising and I step on the clutch the noise goes away, also when deaccelerating the noise diminishes. I'm wondering if it's a bad bearing on the drive shaft. I'm also thinking if it could be anything else such as the wheel bearing? Again the noise goes away when the clutch is engaged, also the whine is ver faint below 50 mph. Thanks in advance...

Edited June 12, 2015 by kamran66

[JFP in PA]

Hi folks, I just picked a 2006 Boxster, car looks and runs great except for a gear whine in 4th and 5th, it gets very noticeable at around 2700 to 3000 RPM. When I'm cruising and I step on the clutch the noise goes away, also when deaccelerating the noise diminishes. I'm wondering if it's a bad bearing on the drive shaft. I'm also thinking if it could be anything else such as the wheel bearing? Again the noise goes away when the clutch is engaged, also the whine is ver faint below 50 mph. Thanks in advance...

 

It could be one of the CV joints on the axles, but I would also look at the front motor mount, and consider the possibility of a gearbox bearing.  It is going to take some diagnostics to isolate which one it is.  The CV's should be easy, look for excessive play and torn boots, the front motor mound I would look for tearing or settling of the mount, the gear box is going to take a bit more looking.

[kamran66]

Thanks for the tips but do you think the CV joints can be ruled out since the whining is only present in gear? In other words shouldn't the CV joints be making noise weather in gear or not? If yes then this rules out all but the differential? Am I right in thinking this?

[JFP in PA]

Thanks for the tips but do you think the CV joints can be ruled out since the whining is only present in gear? In other words shouldn't the CV joints be making noise weather in gear or not? If yes then this rules out all but the differential? Am I right in thinking this?

 

Not really; the CV's are "loaded" when the car is in gear, and unloaded when coasting, so I would still check them.