Engine/Transmission (1994 - 1998) trans trouble no overdrive a/t 1997

[GFelix]

if any can help i have a 1997 4x4 a/t with a gearvendors overdrive the truck only goes into third does anybody know how to check some of the reasons why its not engaging 4 gear please help thank you

 

[Howard Durand]

The truck should shift through the 3 gears automatically then into overdrive at a speed dependent on throttle position. Following that the torque converter should lock up.

If it is not getting past third gear. No OD or TC. It sounds like the Throttle Position Sensor is defective or disconnected or the control cable to the transmission is either disconnected or there is no control voltage.



Is the OD Off light lit?



A little more information is needed. When was the Gear Vendors OD installed? Did it work properly before that?