Need help! While out on the last wheeling trip we had stopped to spot for someone. When I got back in and put the jeep in gear it wouldn't move. Engine would rev but no movement then after few seconds it kicked in and you could feel it grab. Drove fine until you stopped for a short period and put it in park. Jump to this weekend...I had new gears installed and was driving it home in 4 hi never above 55mph. After letting it sit for 45 minutes or so jumped in it to check 4 lo and lockers and they worked but again the same problem when putting it into gear from park. I let it set about 20 minutes, jumped back in and the check engine light came on and warning that said "Hot Oil". Any ideas???