Hello to all, here is the problem i am having
2000 Diurango, 5.9, 46RE, 2x4
Trans has less than 2000 miles on it, when rebuilt all the internal electronics was replaced. I know for a fact it was done and done right because i was present for the entire romoval, rebuild and reinstall.. PCM is less than 1 year old.
A couple of weeks ago it decided to downshift to drive at 85mph. after letting off and on the accelerator a few times it shifted back to over drive and converter did lock. It has done this a few more times since then, sometimes it will down shift then shift right back up, other times it will downshift and stay that way until i almost stop the let it shift right back up. I get no dash lights, codes or any other problems with it. This past weekend i dropped the pan, nothing looked out of place or anything else. replaced filter and put pan back on. drove it around town a couple of days with overdrive off. This morning i had to get on the highway to go to an appointment, 70 mph for 15 miles no problem, on the way back it did it again.
I am out of ideas and need help. I am not mechanically illiterate. I do know what i am doing mechanically and electrically.

 

I'm not sure I completely understand.

 

Ok, its doing exactly the same thing it would do if you were to turn off the overdrive with the shifter button.

 

Sounds like a faulty OD button or the shifter solenoid, but that's just a guess.

I just had to replace my solenoid shifter A and the part was really expensive. I certainly hope it isn't that. The part alone was well over $300.

 

the od button is working fine we have traced it back to the pcm and it goes off and on everytime its pushed. We replaced the shift solenoids as a unit when it was rebuilt. have checked the wiring and plugs on tranny. of course that doesnt mean the parts we installed havent gone bad already. you paid $300, i bought mine from summit racing for $68 and mine were borg warner.

 

Well after driving it around a couple of days in town with overdrive off now it is doing the same thing in drive, not as often but the same thing.
Totally ;lost now

 

It appears you just 'being present' during the rebuild process didn't intimidate the trans enough to run right. This is not a tough call to me, something in the rebuild didn't go right.

If you paid the rebuilder, take it back there. If you didn't, maybe you should have. I do everything on my vehicles, but I paid a guy (a lot) to rebuild my trans and pump up it's volume in the process. It's been perfect since then, over two years now.

 

It sounds like something in the valve body is sticking. Well i do have a spare rebuilt transmission i know is good built by TCI. It would probably easiest for me to swap out the valve body and see before i pull and swap it out. The spare has all new electronics. Next would be my PCM before a complete swap.
Just thought someone here might have had the same problem at one time.
My wife saw the last reply and she told me she would do some serious intimidation with the cutting torch.