What model format are you using for the tank?
EDIT: Oh, I see from your site it's milkshape. Do you make use of a skeletal system for animation?
No skeletal animations. The model consist of a couple of groups -> turret, chassis, gun, wheels and tracks. From there the game engine can identify all parts and move them individually the way we want, ie rotating chassis/turret, elevating gun, adjust wheel position based on suspension etc. The tracks movement is simulated by rotating(moving) it's texture.
We don't know if this will be the final way of making a "JavaWarz-tank", but it seems to work great for now.