In a couple days I'm returning from Tulsa, OK to Boise, ID with a friend who will continue on to Seattle. She has a 2003 Cummins with an auto tranny.

On her way out here, when climbing the grades in WA and OR (6% for miles) and here are the symptoms. She was driving around 40 MPH at about 2500 RPM. Both with and without OD lockout on, the RPMs would spike to 3500, it would lurch forward briefly and then drop back to 2500. She was able to back off a little and it isn't as bad. This is with a 40' living quarters, 5 horse trailer, 4 horses, full load of hay. I would guess 16-18K of trailer.

I don't know the dodge tranny at all but this sounds like when the allison torque converter unlocks or maybe the dodge tranny tries to downshift but doesn't have enough smarts to realize the downshift would put it over redline.

Are these symptoms of common tranny problems? Typical behavior?

that's a slushbox for ya...

it could be the trans tried to downshift, or the lockup unlocked in 3rd allowing the engine speed to increase

That sounds like the same problem my Hemi had......exactly the reason that I got rid of it!!! I would say I have pulled a hill (not 6% for miles) with my Cummins and gooseneck and backhoe loaded, as that is the heaviest load I pull (12K-13K with trailer) and have not had any symptoms like that. I have noticed that it does seem to shift completely different under load than unloaded, and the driving style and conditions also make drastic changes. I would say to have her get it checked out, but the guy told me that unless I pulled the same way, under the same conditions, the problem (if there is one) would likely not duplicate itself. I asked him if had about 3 hours to spare...he said no, so I said I can't duplicate it then. I think it pissed him off, but at least they looked it then. I don't know that it was problem with the Hemi, but I wasn't taking a chance.