You can find a lot of threads on HST fan replacement by doing a "search", but essentially the BX transmission is cooled by a small plastic fan on the under belly of the tractor by the HST filter and is susceptible to being broken by an errant stick which costs a boat load of money to replace. The newer models should have improved protection, but there is still some vulnerability. Crawl under there to check and make sure you have the updated cover and if you are comfortable with the level of protection.
Mine had the old style and I didn't like the new style too much and got some Bro Tek, others feel Kubota's offers sufficient protection.
Some don't like Bro-Tek as some debris may collect in it, just an individual choice we all must make.
