Ticking noise from 190e manual transmission when not under load

Hello all

I have a problem with the 5 speed manual transmission on my 190e 2.0l.

At speeds below about 20 mph I have a wierd ticking noise coming from my transmission whenever there is no load on the transmission. By that, I mean when accellerating or under engine braking there is no sound, but when I change gear or kind of coast on a level road, the regular ticking starts.

The frequency of the ticking is related to road speed, and makes no difference if the clutch is in our out. Above 20-30 mph, the noise seems to disppear. The sound makes me think that perhaps there's a universal joint with too much play, but it doesn't feel that way when I lift the car and turn the wheels. Also, there doesn't appear to be anything fouling the propshaft, and I can't get the noise to reproduce itself when I lift up the car.

Any ideas?