When CMHR shipped a cart across country we had a special box made to protect the axles. UPS would not take it so it had to go by truck. When we talked to Jerald
they advised us not to completely disassemble the axles from the cart. It wasn't cheap but didn't want to ruin the cart.
Yellow Freight. not cheap. but does a good job. have to put it on a pallet and stand it straight up, strap the wheels down with cut tire pieces and tie shafts up with long bungee straps. if you need photos, PM me. I have shipped about 8 carts this way. or call some haulers and ask if they can put it in the back of the truck.