My good friends owns this. it has been raining quite a bit here. he pulls it behind his truck to deer camp, 2 hr drive. this time it rained all the way there. When he arrived and unhooked it would not move. he said battery was low and he had to charge it. He trailer it back. Since then i have installed a new battery. When you put it in gear it feel like something is turning and out of balance in transmission, I pulled the top plug out of tranny. black fluid drained out with small metal flakes. It was driving good before he pulled it down there. My Question is: could the transmission be burnt up?