I run a external tranny fluid filter on my 4x4 chevy, The filter in the pan works good for the most part but when it comes down to a 2,300 dollar tranny I always like to be sure. I use a Perma Cool brand remote filter kit. The mount also has the option for a temp gauge wich I also run. The filter just gives you about another quart capacity and really helps the cooling. Almost every heavy duty RVer/tower that runs an automatic trans uses a external filter in conjunction with a good cooler.