I have a 2000 Durango SLT 5.9. I believe that it has a 46RE trans. It has approximately 103,000 miles. Approximately 2000 miles ago I had the water pump and serpentine belt replaced and this is approximately when the issue with the trans started. I have performed a check for a code and the only thing it shows is " P Code", no code. I have already replaced the speed sensor.
Here's the issue:
At highway speeds, going uphill and holding the throttle steady, the trans acts like it wants to shift out of overdrive but doesn't. It feels like it lurches and seems to clunk. It will continue the lurching until I actually throttle down to make the trans shift out of overdrive. If I manually turn the overdrive off there is no issue at all. I don't notice any problems driving in town having the overdrive on.
Without a code, I'm not sure where to start. Any help will be appreciated.

 

There is a thread here on how to adjust your shift cable. (do a search)
I know you said it has no codes but I'd replace or check the TPS. It should though a code though.
OT. Isn't the English language strange.

 

Thanks dolittle. I did forget to mention that there is no change in the RPM's when the trans lurches. That is of course, until I make it shift out of overdrive.

 

Have you checked the trans oil is it full and is it red or brown. I service my trans at about 60,000 change the filter and adj the bands. Have you checked the shift cable
Is the trans full. You will have to do some checks and let us all know what you find.

 

When was the last time you checked your trans fluid and did you do it running at operating temperature (after about 15 miles), after switching in every gear all the way down held for 2 seconds in each gear and all the way back up, then put it in Neutral and check the fluid level. Only use ATF+4 fluid!

 

Trans fluid was last checked, as you described, when I changed the speed sensor. It was full before the sensor change and topped off after the change. Kept track of the level for a couple weeks after that and saw no change in the level.

 

i would adjust the tv cable
directions in the pdf at the link below

http://www.mediafire.com/?4z89ndodf38txbr

 

The TPS solved the problem. Thanks.

 

Thanks for the update kitty!

 

I had the same thing going on. going uphill or even at a steady 55 or 60 i"d give it a little gas and it would do this chatter shudder thing til i either floored it or slowed way down. Went and had it completely flushed and problem solved.. thought i was going to need a new tranny,..good luck