I bought a 2000 Dakota Sport crew cab with the 4.7 L 4wd auto trans. 138,000

I drove it for about 500 miles and all was good. I decided to change all the fluids. Everything went good. I changed the transmission fluid and filters, the fluid was a good red color and there were no metal shavings in the pan. I got everything back together and took it for a drive, the truck shifts from 1st to 2nd but wont shift into third and just revs. I took the transmission pan off and changed the filters again, I made sure the filters were tight. I primed the filters. Still had the same problem. Fluid level is good. I replaced the input and output speed sensors and still had the same problem....Not sure what do do next? I had the codes pulled and they are
P1790
P0733
P0734

Not sure if I need a new transmission or...

 

Did you use OEM filter and fluid?

 

No. I used ATF +4 STP fluid and Filters from Rock Auto...

I also did have the codes cleared multiple times and it keeps happening

 

http://www.obd-codes.com/p0733
http://www.obd-codes.com/p0734
https://dodgeforum.com/forum/dodge-m...s-it-mean.html




P1790-FAULT IMMEDIATELY AFTER SHIFT
After a Gear Ratio Error DTC has already been set. The DTC is set if the fault happened within 1.3 seconds of a shift. The DTC set time will vary from 1.214 seconds to 15 seconds

 

Are you sure the oil filter O-ring is in place? I'm talking the pick-up screen. I may be wrong, but I vaguely recall that with it missing, it wouldn't build enough pressure to shift??? You also want to be sure the old one came out and they aren't doubled up in there.

I changed to an aftermarket spin on filter then switched back to mopar. The mopar filter has an anti-drainback valve. AM does not.

 

Change the filters to Mopar.

 

I put in mopar filters and the result is the same..... It shifts into Reverse and drive good and when you drive it shifts from 1st to second smooth and when you are in 2nd and get to where it should shift it studders a little and then revs like it is in neutral.

So far I have put in new input and ouput sensors and trans oil pressure sensor in. Today I removed the valve body and there were no loose bolts or damage or anything to the valve body or accumulator plate.. I am at a loss here

 

What about the O-ring I mentioned? It goes on the neck that extends up into the tranny as pictured here. Without that tight seal, there is loss of suction for the fluid entering the tranny and therefore, starvation. Again, check to make sure the old O-ring didn't get stuck up in there too. Doubled up es no bueno. There should be a rubbery snap when you push it in and the o-ring seats. Coat it with ATF before installing.

 

Yes...all three times i removed the existing o ring and made sure the new one was seated properly and the filter popped in

 

I just did my pan and filters on Saturday, used Adv auto for the two filters and have had no issue, just logged about 150 miles on it. You really had me worried with your scenario