Unlike the European crews...American crews had to do most of the maintenance and repair on their tanks. I, just a lowly Tank Commander/Plt Sergeant, had to explain short tracking to the German mechanics who were trying to get a leopard back on the road after it lost it's rear set of road wheels. The crew just broke out their rations and sat on the tank watching us work.
That would never Fly in the U.S. Armor or Cavalry. The American Crews worked and learned along side their mechanics so if they were broke down in combat they could get the tank moving and get back into battle.
Combat repairs were taught to and improved upon by our crews.