2003 Lincoln LS with 135k miles 6 cylinder
Reverse is one of the more precise gears in the transmission and being that if there is an issue in the trans if usually effects reverse first. Could be regular gear wear as it has high mileage or it could be that it has some bad fluid. If the transmission cooler is blocked it could cause the fluid to overheat and become thicker. So check the fluid, check for metal fragments, if both of those look good then it's just normal wear and tear most likely. Transmissions can take a long time to truly die from the first signs of trouble till when replacebt is necessary. Also try to find forums for your car as each make and model may have specific issues to look out for
planetary gear set clutch plates are bad.
