I just recently bought my 97 dakota v8 4x4, it will not shift into overdrive. The transmission was rebuilt in may of 2011 by a shop by the previous owner. I have replaced the overdrive solenoid as well as the governor pressure solenoid and transducer with no luck. I have taken it to a couple different tranny shops and they drove it around with the scanner hooked up and said that everything seems to be looking ok and everything is telling it to shift but its not doing it. Also it is throwing code 0783 for 3-4 shift malfunction and when driving over 40 and I hit the overdrive button to turn it off after a few seconds the rpms will drop a couple hundred which I believe is the torque lock up but it is still in 3rd gear.

Both shops wanted at least $150 to diagnose it and then if its internal they wanted minimum of $2000 to find and fix it and if it need to be rebuilt they wanted around $3500.

So I'm hoping that someone here on the forums can help me out, do you think that the overdrive unit could have been rebuilt wrong? Previous owner said that it worked after they got it but then when out and believed it to be the solenoid. Could it possible be TPS, although it idles fine and doesn't hesitate when driving. What about clogged valve body? I understand that the overdrive unit is controlled electronically and hydraulically so I have the PCM and the valve body, if the scanner read that it was giving commands to shift but not doing so could a valve just be getting stuck?

Any input would greatly be appreciated.

-Jaime

 

Have you checked the fluid level?

 

Yes, that was one of the first things I checked and it was good then I changed the fluid along with the filter when I replaced the solenoids.

 

Don't know your location but, that's WAY too much money for a trans shop to
tear into it & re-build it. More like 1100.00 for a re-build with a new converter.
I've got a guy that has a good shop near Chicago that will rebuild it for around
the price I mentioned. 2 yr warranty also.

 

just above the 8 pin connector on left side of trans is an 1/8 NPT test port for OD...You can attach a pressure gauge ( at least a 150psi) and see if pressure is there when 4th is commanded....If there is any noticeable pressure then the shift was commanded and the shift valve did stroke, so the problem would be in the OD clutch itself....If there is ZERO pressure then the shift was not commanded or the shift valve did not stroke, but no mechanical error would cause ZERO pressure.So to answer your question, it could be a valve body problem, but only if there is ZERO pressure when 4th is commanded...If you have full mainline pressure when 4th is commanded, then electrical and hydraulic system is ok, its mechanical..

 

Thanks for the input, I just pressure tested it and it commanded it but I only got about 15psi, and from what I've found it should be between 68-130 depending on throttle position.

Do you think that this means that it is a mechanical failure with the overdrive clutch/unit or could their be a clog somewhere?

 

3,500 for a rebuild! Tell them to gfym lol I have been quoted 1,500 by aamco for a complete disassemble/reassemble and rebuild with a 18mo/18k warranty.

 

3,500 for a rebuild! Tell them to gfym lol I have been quoted 1,500 by aamco for a complete disassemble/reassemble and rebuild with a 18mo/18k warranty.

 

Yeah I know and aamco was actually the place the quoted me that price. I have no problem buying a rebuilt transmission and put it in myself. Most shops I talk to want to pull the tranny apart to find the problem then charge an extra $1000-$1500 on top of that to rebuild it.

But I'm going to drop the pan again tomorrow and check the line pressure and adjust it if needed and hopefully that will fix my problem.

 

with low pressure, it would be apparent that a massive leak has occured, probably the OD clutch seals....Also there is a plastic orifice in the OD piston housing that will dislodge and bingo , no fourth.....You could pull the pan and then apply air into the 4th clutch test port and see if you can find the leak....