Hi guys, question for you all. What is your Rpm when cruising at about 55? Mine seems high at almost 3000, and I seem to be only getting three gears in my transmission, when overdrive is supposed to act as 4th gear in this tranny. Switch does nothing in any position, and doesn't light up in any position, or on start up. Ideas? Thanks.

 

are you driving a charger or a z car? help to know what we talking about here. 240,260.280.280zx.z31.z32 and on into the 2000. if you are talking about a z31 which is where you posted they don't have 4 spd tranny. slush box probably shot they usually are by this time

 

ALL Z31 automatic cars have a 4 speed overdrive transmission.

The 4th gear overdrive has a shift solenoid that my have a bad connection. Check the wiring and the connector on the transmission and the selector button.

The overdrive switch in the automatics has a temperature sensor that does not allow the transmission to shift into overdrive until it is sufficiently warmed up to avoid possible damage. This may be your problem.

XenonZcar.com Z31 Transmission Specifications and Variations

 

Thanks for the helpful response, I'll be sure to inspect those points.