Hi there, i own a 1991 mitsubishi l200 pickup truck. I've had the clutch disk and cover replaced recently and now whenever i'm in neutral there is a rattling/chattering or knocking sound from the gearbox. It goes away when i disengage the clutch or if i raise the rpm's to about 1k+.

also had all the bearings in the gearbox including the release bearing replaced.

should have changed all the clutch parts, could be throw out bearing or pilot bearing. Most guys put in a whole kit to make sure nothing goes wrong in that big job