Picked up a 1998 used NV 3500 transmission yesterday from junkyard yesterday and hope to get it in this weekend. What are some of the manual transmission fluids other NV 3500 owners are using and your thoughts on that fluid?

I think our 'new' transmission set for a long time and has been pulled for a while too due to the size of dirt dauber(sp) mud runs on the outside of the case. Case not very greasy compared to our 524K mile NV 3500.

It still had some fluid in it that may have been OEM. It was dark honey color but you could see the concrete floor very clearly through it.

 

Buy Pennzoil Synchromesh Manual Transmission Fluid (32 oz.) 3501 at Advance Auto Parts

Royal Purple SYNCHROMAX - Manual Transmission Fluid | O'Reilly Auto Parts

Price may be the only differences between these to options of our NV 3500 5-speed transmission. We plan to do a flush with the cheaper Pennzoil then run Royal Purple longer term.

Flushing is NOT required but just a $16 item that I want to do. It seems that our 'new' NV 3500 5-speed has set for a long time before and after it was pulled. While it was stored under a roof the shifter mounting location was open to air and something may have build a nest inside if that hole drains into the case. Not sure as to how long I will go before flushing the Pennzoil out to fill with Royal Purple for the long haul.

I think the fluid that was left in it may have been from the OEM fill. When I do the drain down I can see if it is still making metal. There was no more than the normal amount of metal on the transmission drain magnet when I cleaned it.

At first I was going to do a short run on ATF or 5w-30 engine oil but the pennzoil option was not much more for the real thing.