I had a chance this weekend to replace the differential (rear end) fluid in my 2017 Toyota Tundra SR5. I used AMSOIL Severe Gear 75W 90, it is a GL 5 fluid. First, I cleaned the exterior of the truck and took it to a touchless carwash to clean the bottom. After the vehicle was dried I sprayed AMSOIL Heavy Duty Degreaser on the differential cover and wiped everything off. I made sure the differential was completely dry and free of any contamination. Besides a magnet to attract ferrous particles, there is no filter element on this differential. If you get debris inside of it, it will keep circulating and potentially eat away at your gears. I put the vehicle on a level part of my driveway. I then used a 24MM socket to open up the fill plug first. It is a good practice to open the fill plug first. If you drain all the fluid out and can’t get the fill plug off, you could end up having to drill out the fill plug and remove the cover to get the shavings out. I then drained the old differential fluid. I was surprised on how dark the fluid was for being under 5,000 miles. It was not that bad but I did see a lot of metallic particles floating in it. I read on a few forums that this is normal for breaking in a truck. I don’t like the suggested drain intervals. In my opinion, you should do an initial differential fluid change around 5,000 miles. After the fluid was drained I cleaned off the magnetic end of the bolt. I then lubed the threads with new gear fluid as a good practice. I then installed the drain bolt and torqued it with a calibrated torque wrench. I pumped the Severe Gear 75W 90 into the differential and reinstalled the fill bolt. I did a double check on both bolt torques and took it for a test drive to see if it leaked. You don’t want to over tighten the bolts. If you over tighten, you could snap the bolt or crack your differential. I am trying to find the factory workshop manual for a 2017 Toyota Tundra SR5. These are more detailed than the car maintenance manual you get when you buy the car. They are the manuals that the mechanics at the dealer use. So far, I replaced the oil and differential fluid with AMSOIL products. My next goal is to replace the transmission fluid. I have not found a solid writeup on how to replace the transmission fluid. I am looking for one that shows you how to remove all the fluid at once. This Toyota Tundra feels like a solid well-built truck. I am not a fan of the bad has mileage. I am not a full throttle on the entertainment side, but these basic speakers have to go.