Truck stalls in reverse and when going slow, also shifts hard and slips gears

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! It sounds like your F-250 is dealing with a few issues at once and that's no good! The stalling, hard shifting, and gear slipping along with the flashing overdrive light, usually point to transmission troubles. Your misfires and lean system might affect how the truck runs and shifts, making the symptoms worse. Start by checking the transmission fluid—it should be clean and at the right level, not dark and smelling burnt. Also, make sure no vacuum leaks or ignition issues are causing those misfires. If everything looks okay and it’s still acting up, you might need a deeper look at the transmission or fuel delivery system. Don't worry too much about the rear main seal leak for now; it's important but not as urgent as getting the truck running smoothly again. Good luck! If you have any other questions, please call us at 877-913-1554! We'll gladly find you a certified RepairPal shop in your area!