Need a little help. My F350 is a V10 just recently I was towing a toy hauler up a grade in 2nd gear and the tranny started leaking oil on the exhaust. Pulled over let it cool and made the rest of my trip no more leaks. Check the oil level and added about 3/4 of a qt. Toke the truck to my mechanic and serviced the trans with synthetic. Then toke the toy hauler out again with no problem on the hywy got on surface streets up a short climb and it started poring oil again this time the exhaust caught on fire put that out let it sit for a little bit drove home (about 4 miles no leak). Any ideas? HELP

Thanks Ron