At what speed, MPH are you going. There is a MPH maximum by design were the transmission will not kick down two gears, it places a tremendous load on the transmission at that speed. You owners manual has the kick down shifts points. if you are within the shifts points then.


Check working, govenor and modulating pressures.

Open the passengers’ side door with the ignition on, floor the gas pedal, you should hear a click at the rear of the transmission if not check the fuse for the kick down solenoid, good fuse, check for 12v at the kick down switch under the gas pedal check for a stuck kick down switch, 12 v; check for 12v at the kick down solenoid, 12v; defective solenoid.

Check and adjust the Bowden cable, check the modulator vacuum lines and connections for leaks check for manifold vacuum at the modulator line.

And the most important vacuum check especially for diesels is a vacuum drop test. With a vacuum gauge connected to the modulator vacuum line, open the throttle, the vacuum gauge should immediately drop to “0” vacuum, if not then you have a bleed off problem which will gave you flared up shifts , slipping and no kick down.