The flash point on trans fluid is very low. Two years ago and the W C race in Bristol, Tenn a guy had a brand new F250 crew cab short bed 4wd with a fifth whell trailer on the back. He was backing up a steep hill when poof. Everybody started yelling I turned around and flames rolling out from under the truck. This guy backed the trailer and another unhooked it he pulled forward and the truck burnt up. But at least he had a place to stay. I heard that the trans fluid came out of the dipstick tube and on exhaust from backing up the incline.