Just traded in my '03 duelly. (230,000) Pulled a 40' cargo trailer most of the time. I can't remember mileages of replacement parts, but here is my repair list. Nothing under warrantee! on trade-in the truck is over heating, the fan is not kicking in, and there's a sever oil leak, I think it's the front main seal. Here's what I have replaced. 2-NV-4500, 3-clutchs,3- u-joints, 1- carrier barring, i- drive shaft, 1- lift pump, 1-injection pump,1- turbo, 1- belt tensioner and belt, 1-alternator, 4-rotors, 2- rear callipers, 1-power steering pump, 2- batteries. I do not abuse my trucks, I do put on a lot of miles. I run synthetic oil and change every 5-7000 miles. All in all I still think it's a good truck, after all, I traded it in and bought another