Technical Thud when Changing gears or on pullaway

[yuthimon]

Can any body explain why when i pull away in fiat brava 1.6 16v 98 i get a thud that seems to come from the gearbox as its putting torque on the wheels. when i change gears i get the same thud. its almost as if i only get it when i release the torque on the wheels then put it back on. Seems like something is loose somewhere but i cant find out where. Any Suggestions?..
Thanks...

 

[guido]

Have you checked the engine or gearbox mounts?