I have 2 (2001 1500's ) Off Road Pkg, Both with automatics & 4:10.1 gears, My wifes 2001 has 110,000 miles No problems at all , My 2001 89,000 miles & lifted with 35's & 4:10.1 gears No problems at all. I do know that on Automatics when you service you are recommended by Dodge to add an Additive designed for Dodges with automatics.
You can buy this additive off the shelf at any parts store.It's called TRANS-X.And it works it will clean gumned up seals and swell them back to life.Most problems start with an internal sealing problem caused by gum deposites.twotones slipping reverse would benifit from 1 pint of this stuff.TOYOTA uses it in there ATF.I've used for 15 years as a preventive maintenance and never had a problem out of my Chevy's.
Something I learned in a GM class at work.At 200 degrees todays ATF WILL NOT break down.But at
350 degrees it's trashed in 15 minutes.So if you tow or have larger tires or off road and don't have an external trans cooler...GET-R-DONE!!!These trannies in these heavy trucks have to be serviced to last.
There's also a silocone additive out there to help with keeping the solenoids lubed up,to keep them from sticking but I don't know what it is.
NK sounds like the dodge fluid works good