Water in 2005 frontier transmission that was brand new I was told it had something to do with radiator hose or something and they bought a small transmission fan to be put on.I was also told something about this happens when you tow with a truck or something I can't remember.I don't even tow.
Nomadd: It has water because the transmission oil cooler inside the radiator is leaking. You need to replace the radiator and flush the transmission. It has nothing to do with towing.
Only two ways water gets into a transmission. Someone poured it in there. Or the radiator went bad between the radiator core and the transmission coolant lines that run through the bottom of the radiator.
Either way, water in the transmission means a new transmission.
Nissan had radiator problems with the transmission cooler. rotting internal and mixing anti freeze and transmission fluid. (google it to find numerous complaints) find more help at ATRA.COM for more help