I changed all my fluids. I'm also one for changing oil in a car at the first 1,000 miles. I figure the breakin period is going to have the biggest chance of metal shavings and such. Oil is relativlely cheap compared what I paid for the equipment. The best way to get rid of contaminants in the oil is to change it. I also have a diesel truck and Rotella T goes in also after the first oil change. The strainer sounded like it was going to be a mess if not drained, so drained it was. My strainer looked pretty good but cleaned and replalced, refilled with super udt-2. I aslo drained and replaced the front axle fluid too. Only spent $150 overall for the full fluid change and filters, cheaper than the dealer. My machine and I feel better.