Engine/Transmission (1994 - 1998) Transmission fluid (manual 5 speed NV4500)

[KHouse]

I was wondering the best transmission fluid to use on my 1997 dodge ram 2500 cummins 5 speed. It has a NV4500 transmission in it. I have seen lots of different fluid but I wanted to know the highest recommended for that specific transmission. Thanks.

 

[Joseph Donnelly]

Around Issue 33 I reported tests on HP drag of different fluids. I found for keeping the trans temp low, and low drag, either Castrol Syntorq or Torco RTF was best. I like the latter because it doesn't seem to degrade and make black slime like the Castrol, and with a GL6 rating, should protect ther gears from breakage better. It does not attack the brass parts, unlike some GL5 and GL6 rated oils.

 

[surfbeetle]

It's funny over the course of the last few days, there are three different threads concerning the proper oil for the NV4500. There are many many threads already in the archives that also address this. With that said, I have used Royal Purple for over a decade in my trans. My trans has 225,000 miles and has only been out at 180,000 to have the clutch replaced when the pressure plate failed. The trans is still original factory and my fifth wheel is 11,000 lbs.