This is my first post and I just bought this truck. So far so good. Owner took really good care of it and it only has 35,000 miles on it. I really want to keep it up, so I had some maintenance questions. The previous owner said that it always had the oil changed at the dealer and tires rotated, but that's it. Do I need to change anything else like rear differential oil or anything. What about coolant or that kind of stuff. The maintenance guide just says check it all but not to replace it. Any suggestions would be greatly appreciated. I hope to keep this thing a long time.