My transmission will not stay in overdrive.
Q. My transmission will not stay in overdrive. It has gotten more sensitive over time. Originally it would kick out of overdrive with fast acceleration or by using rocker switch. Is there an adjustment for this?
A. Wish I could help but I need a lot more information. I’m assuming it’s a Vette but what year? What engine? What transmission? Is it 2 speed, 3 speed, 4 speed, 6 speed, 8 speed? Depending on the year and transmission it could be a basic throttle valve adjust up to reprogramming a computer. But one thing is universal among all automatic transmissions — hydraulic pressure. Every automatic transmission relies on hydraulic pressure to perform shifts and if that pressure is not right the transmission will not shift properly. So no matter year make model, etc. the first test is a line pressure test. Line pressure testing determines if the transmission is mechanically sound and can produce the right pressure for it to work right. I always start with line pressure so I don’t waste a lot of my client’s money trying to fix or diagnose a transmission that will never be right without internal repair.
Originally posted on National Corvette Owner’s Association newsletter http://www.nationalcorvetteowners.com/