Yeah I checked the fluids levels, and the auto fluid was good but I added some Lucas tranny fluid just to top it off. Out of curiousity I have been reading a lot about people having noise issues and the O/D locking and unlocking, could this possibly be my problem?

 

Could the symptoms of a OD locking and unlocking fit mine, cuz it kind of seems like they could, so I'm gonna see if I am getting noise

 

That really wouldnt explain the lose of power though. The trans could be overheating. Im not sure if your truck has a check valve in the cooler line or not. Next time it act up, pull over and carefully fell the trans cooler to see how warm it is. If both lines are cool, then its probably overheating and foaming up.

 

RRussock

I saved up money and finally got my 2001 4x4 2500 ext cab long bed 24v turbo diesel. 145k miles. Sorry to hear about your issues. To share, the one I bought was slow to shift from 3 into OD about twice, but checking the fluid and doing the one quart high thing helped.

The truck had been used by the previous owner as general transportation and did a 5 minute commute to and from work without getting over 45 mph. Took him 7 weeks to burn a tank of fuel. When I got it, I tanked up with new diesel, let a bunch of water out of the filter, then got on the highway and drove 100 miles with 1500 lbs of lumber in the back. It has progressively driven and shifted better since then.

What I am suggesting is that the difference between your use and the previous owner's use could be at issue here. Not sure, just an idea.

 

RRussock, Not sure if applies here, but my 01 shifted well below 2300. Last shift???? You mean last gear or converter lockup? Where problem comes and goes, sounds more like trany system - electrical.
Good luck