JenCho, to be honest I can't remember seeing a odometer read 100k in the last 20 plus years. As I always buy used for cash. That being said, if you have keep up with other scheduled maintenance , oil/filter changes , tranny fluid, checking diff levels, and if you have them grease fittings. If you have not had to change brake pads, double check them. About now , 100k, you want to keep notes of anything that changes. That new noise you never heard before, that slight pull when stopping or starting. Most trucks just start to settle in at about that point. Something changes check it out or have it checked out. I'm getting to old and newer vehicles are so complicated with everything computer controlled, I hear a new sound or a new shimmy I head to my mechanic, he's 3/4 of a mile down the road, know him well. It always helps having a good relationship with him. It's got me out of more than one bind when I needed it . He also knows everything that has been done to it, that makes life easier. Good luck and happy trails to your next 100k.