We have or have had 11 dodges (95-2001),all diesel,all auto,all get plowed hard.One had a trans problem,which was rectified by a TPS adjustment.Most of these trucks now have 160-180,000 KM.Fluid and filter,plus band adj done every 20,000 KM,or annually.None of our Fords made it that far.Our chevy's have been just as good except for some planetary failures.
If your looking at a used one,94 and early 95,weren't that great,the 96 are OK,97 and early 98 (12 V Diesel) are the way to go.
There are also many good auto trans parts available to beef the chryco auto up if you wish.Aftermarket valve bodies and convertors are a big help.My personal truck (97 12 V diesel),has a valve body,TorqLoc and convertor from BD,and it handles the 275 HP,680 FtLbs of the modded Cummins no probs,pushing an 11 ft plow all winter.Now...if i could only keep driveshafts in it ....
Chris