Can I use ratchet straps to lift a dolly into a truck bed?
Having had to manhandle quite a few appliances on my own I would do this. Put the truck tray down. Tip the appliance over until the top just rests on the edge of the tray. Lift the back of the appliance and push forward. Use cardboard under it if you don't want to damage the side. Once it is all in, stand the appliance up. This way you are never deadlifting the appliance, more pushing and rotating it. You can use rachet straps like lifting straps to get better purchase if you want.