Jerry, the original axles were a bit short and at full articulation for steering could fall out. I remedied mine by moving the cups out a bit. As for the rotation unit, mine and yours doesn't come with it. It was released well after we received ours. Should work on the Puma. Also Ludwig has an offering for the rotation as well. Also the gearbox needs some shimming which they now include a couples thin washers. The crown gears are pot metal and don't think they'll survive much actual r/c use, haven't found a replacement for those yet.