2006 Ram 2500 diesel reliability past 135K?

I have a 2006 Ram 2500 Diesel with 48RE auto transmission with 135K miles on it. I've kept up the maintenance on it and in addition to that, had most ball and u-joints replaced plus most of the hoses. I have some of the "common features" like tach is wacky and heater won't blow on floor. It's showing some aging like rust on rear fenders and drivers seat cloth in bad shape. Lately on occasion (not a lot) it will start rough or take 2 tries but runs fine after that.

I changed the oil and filter, air filter, and fuel filter today. Underneath is showing more aging after the winter with quite a bit of rust. The oil pan has a little leak at the seal and has bubbles all over the bottom of the pan now. It didn't have those last oil change.

I pull a fifth wheel with it and this year we have a 1100 mile round trip plus 3 other 400 mile round trips. I'm wondering if it's going to start having more problems, some possibly major? I haven't had any engine or tranny issues yet and all seems well right now. With all the miles and more rust showing up, it is maybe time to trade it in?

Just wondering what others have experienced with their trucks? Is the engine and tranny generally good to 200K or am I in the range where things can start to go South?

Many have gone far more miles than yours. Some early Ram/Cummins passed the million mile mark. So far on my '05 with 134,000 miles I have had the drivers seat recovered and the radiator fan clutch replaced. That is it besides routine maintenance and tires/brakes/batteries. I plan to go lots farther with the truck. No rust, we live in the driest state in the nation.

Get an Edge Insight or similar and you will be able to monitor pressures and temperatures (especially transmission) lots better than the stock gauges.