I have a 2002 Ford Focus 5 speed manual transmission that makes a grinding type noise when it's in gear and moving.
When the car is idle the noise stops and it even stops when moving down the road if the clutch is pressed in. As soon as the clutch is released the noise is back.

Any Ideas what this could be and how much it will cost to repair?

Thanks

Kevin, March 2008

Lack of oil (transmission)
Input shaft bearings worn

Worn, damaged or chipped gear teeth

Iliev, May 2008