I have a 1994 Dakota, it shifts fine through all the gears but will not shift into overdrive. To be sure that I wasn't in overdrive, at 3K RPM and about 70 MPH, I hit the OD Off button and nothing changed.

Is it common for Overdrive to go out of these vehicles? Would ONLY OD go out and the rest of the transmission be fine? The fluid level is fine on it, I've seen much worse looking fluid than what I have. I don't want to spend the money getting it changed and then find out that I need to rebuild the tranny.

Are there fuses, computers, etc. that might be causing this?

Thanks as always for your help.

 

my 90 did it when was still under warrenty they fixed it in 15 min. Then again my 90 did it at about 80K miles and was the start of the trans going out. guess i am no help!!

 

It is possible it is the transmission solenoid. But check the wiring and switch for correct power and all. You can check the FAQ in this section for the wiring diagrams.

Are you getting a check engine light. A bad speed sensor can cause this. In most cases a CEL will come on. Check all connectors are plugged in tight.

 

Check your speed sensor wires with a multimeter and the speed sensor itself. I had the same problem and found that my speed sensor wires were cut.

 

Okay, now to expose my ignorance....where is the speed sensor located? Some place on the tranny?

Thanks again for all the help.

 

If your truck is 2wd, the speed sensor is at the back of the transmission on the drivers side. If your truck is 4wd, the speed sensor in the extension housing of the transfer case, again on the drivers side.

The overdrive unit is electrically controlled, so chances are your problem is electronic and not a mechanical issue with the transmission.

 

Thanks again everyone!!

95_318SLT, is there a chance that the speed sensor is called something else? I'm not finding that when doing a parts search at the local autozone. Is it something that would not be carried by a place like autozone or O'reilly?

 

I'm not aware of any other name for it. The factory parts manual (available for download on the faq page) lists it as a speed sensor.

 

Thanks again. I will keep researching it and jump over to the FAQ. Hey, one more real quick question...is this located up toward the top of the transfer case and a little hard to get to? Or is it right out there easy to get to? Is it near the speedometer cable?

I really appreciate all your help!!

 

Its something that can be found anywhere I would think. When my speed sensor went, I was able to find one at summitracing.com and at all my local junkyards and parts stores. Its not a cheap sensor tho, but cheaper than a tranny, and I can almost garantee that its your speed sensor causing this issue