First and foremost, there is no need to change the transaxle fluid that often. Once a year should be fine unless you are doing a lot of enduros. There's also a magnet on the inside of the transmission case that picks up the chunky stuff, but it's only accessible during a re-build.
Anyway, the only suitable fluid for use in the NV T350 is the MS9417 Mopar NV T350 transaxle lubricant; p/n: 4773167 (may superseed to updated p/n)
Sometime around '02 or '03, MS9417 was superseeded to ATF for both service and factory-fill due to supply issues (I was a parts guy at a Dodge dealership then). It has since superseeded back to the original fluid, but at a cheaper list price and with a new design lable on the bottle.
The Mopar MS9417 fluid was specifically designed, produced, bottled, and sold for the NV T350 transmission. It is listed to contain unique friction modifiers and that's reason enough for me to use it.
Alternatively, Royal Purple cross-referances one of their lubricants for MS9417 but I have never used it. I've also never heard bad things from people using it or Redline... Who knows, the transmission could be fine with beer for a lubricant!
Dose anyone know of any other fluids that can be used in the neon manual trans? All the manuals that I have read recomend to use the mopar part#. It dose not tell you what type of fluid it is. I am tired of paying the dealer cost .
