I should have my second in November. Very little issues on the first, a couple of wiring breaks and just replaced the DEF level sensor. One other sensor, can’t remember which one.
There was trouble with cams the first year or two (a decade ago), but the last six years have been pretty reliable. I talk to the shop manager at the local KW dealership occasionally about what problems he sees, and they just don’t see much.
On my last truck I had wiring issues where they bundled them up below the firewall where they went back under the cab. Had all kinds of weird lighting problems, like I’d be sitting at home and someone would tell me headlights and 4 ways were flashing while it’s parked over at the shop. Ended up with 7 or 8 broken wires in the bundle. Fast forward to last week, I get a bulletin in the mail for my new truck. Wires bundled too tight on the bracket below the firewall. Lol.
But as far as my last truck, sold it right at 600k. I had to do 2 NOx sensors, the def level sensor, cleaned the dpf once at 250k and then replaced it at 500k, I did do the starter and alternator but can’t remember when.
I have a 500/1850 13spd with 640k on it in a 15 T800 that's deleted. Only major issue I've had was a valve mashed the seat into a knife edge. Pulled the head and put a new valve in that hole and I've been running it ever since. I get around 6mpg and walk off on my buddy with an isx15 at 525.
When I had the head off I snapped a pic of the cyl walls.