I was driving today on the freeway in my 89 Max with a dying transmission I am almost sure of (Gears shifting rough after high RPM's and low speed acceleration) but while I was driving, I switched the over drive button off and it seemed like I had a lot easier of a time accelerating after 1st gear. I really don't know what the over drive buttom does but I know it has something to do with the RPM's but this is kind of like something for me to breath earier about so that I can accelerate at a normal speed then extremely slow and HIGH HIGH RPM's. Any help would help out a lot. Thanx!