Want to keep your automatic transmission running smoothly? Avoid these five costly mistakes. First, driving through deep water can suck water into the transmission, often leading to a complete failure. Second, never switch from drive to reverse while moving—it’ll destroy your transmission. Third, if you’re idling for long periods, switch to park to prevent overheating. Fourth, frequent burnouts will wear out your transmission quickly. Lastly, don’t ignore regular transmission fluid changes—dirty fluid can shorten the life of your transmission. Keep these tips in mind to avoid expensive repairs and keep your car running like new!