Are you importing into swift3D?
Is this animation to be imported into Swift?
If so make sure you don't have any mirrored objects (swift doesn't animate mirrored objects correctly.
If not:
In max just pay attention to pivot points. You can move the pivots to the position you want. By grouping all your objects, the pivot should simply place itself to the dead-center of the group. Once grouped, go into Track view and do all your animation from there. Locate the track for the group and place your keyframes accordingly. This should work just fine.