As long as your moving at speed the fan rarely comes on, when plowing snow at very low speeds it does come on frequently. These small radiators can easily get packed with mud so be sure the radiator fins are cleaned out. I just use a good stream from my garden hose to flush after riding in extreme dust or mud. Yes, do change the diff fluids, I use full synthetic 75/140 diff lube. Mine also has a tendency to stall until completely warmed up, but can also stall if overheated !! With the current world issues shipping from Tiawan can be iffy at best. Not a lot of stocking dealers out there but there are some that will ship.. I have a 2015 450i and it has been an awesome machine, very few spare parts have been needed. If your speedo is not working, try pulling the speed sensor and cleaning it and the electrical connection to it. They are also known to go haywire and need replaced. About 50 bucks to replace mine. Right down there next to the oil fill and dipstick, one bolt to remove and pull sensor out. Good luck with your machine, hope it serves you as well as mine has served me!!
