Engine/Transmission (1994 - 1998) Relation between Overdrive and Bands

[NKenny]

What are the bands doing when a 46rh is shifting into OD?



I cannot get overdrive and am trying to find any reasonable reason. I have replaced the TPS with a potentiometer, plugged a 1K ohm resister into the temperature sensor plug, changed the fluid and filter, and recently adjusted the bands. I was having OD trouble prior to these listed acitivities, but now I have no overdrive at all so I am trying to back track what might be my problem.



The transmission shifts well and lock-up works automatically in 3rd gear. I noticed yesterday that when the truck is cold, the transmission seems to jump into neutral at a certain throttle position (maybe the TV linkage). I don't feel any excessive converter slipping, other than the 2200rpm stall induced slipping.



55 mph just doesn't seem to get me anywhere. Thanks.

 

[Joe G.]

OD is set by a piston in the tail shaft. The bands are not involved. There are three wires on a plug into the transmission. The center one is light green with a black tracer. That one is 12 volts (ignition on). One of the other ones is orange with a black tracer. That one is TC lockup. The other one is brown. It is OD. Rig a wire from the brown wire into the cab and another wire to ground. When the truck is up to the speed that OD should work ground the OD wire and see what happens. If it does not go into OD then you may need a new OD solenoid on the valve body.

 

[NKenny]

Amen! That is exactly the info I have been looking for. I will run that experiment either this evening or tomorrow.



Out of curiosity, is it common to lose the overdrive solenoid?



Thanks Joe.

 

[Joe G.]

The OD solenoid may fail, but it's not a common problem. Something else may be wrong thus the suggested test. There may be something wrong that involves the OD piston or clutches. Maybe a bad or corroded connection in the wiring. It may be hard to find.