I just purchased a 1990 4x4 3.9L Dakota with a few transmission and power issues. First it keeps slipping out of overdrive. Does anyone know what is causing the truck to do that and how could i fix it? The brake light is also on and i read somewhere that, that may have something to do with it. The guy i bought the truck from told me that the light came on after he hooked a boat up to the truck and it raised the front of the truck off the ground. Second, I've driven a few Dakota's before i purchased this one so i know how much power it can put out but this one is kind of weak in the power department. I'm not sure if it's the motor or if it's related to this overdrive problem I'm having, does anyone have any suggestions? Also, I've thought about replacing the transmission all together. Does anyone know what transmissions will mount up to this motor or where i could go to find out? I would like to put a tranny off of a Jeep if possible, but i would like to know all my options.

Anything that is found behind a Dodge 2.5, 3.9, 5.2, or 5.9 would bolt up. Anything behind a Jeep 2.5 would bolt up.

If your trans module or engine module thinks you're braking, it probably wouldn't let you into overdrive. I can't think of why, but it's most likely brake system related as opposed to trans related.

Thanx jhrody,
Does the year of the truck I'm getting the transmission from matter?

I take it back about the 2.5. Any 2.5 trans is going to be lighter duty than one behind a V6 or V8. I'd look at only V6/V8 trans.

I'd stick with an OBD1 donor vehicle. This means 1995 and older. If you can, take the trans computer (TCM) and harness with you, just in case.

As usual jhrody, Thanx for the tip!