I was on Parts Geek looking for a transmission filter and they show what appears to be two completely different filters for a 2001 4wd. One has 3 openings with gaskets on them and the other shows 1 oval opening. Are they just showing different sides of the filter?
What size is the hose on the transmission cooler line?The transmission filter is supposedly a "lifetime" part. If you decide it's in your best interest to get a new one buy OEM.
What most people do is install a magnefine inline filter after the cooler lines. That will clean more than your filter will anyway, just be sure to change it out every 30k miles or so.
What size is the hose on the transmission cooler line?