Yup, Ive changed the fuild twice in my NV in the 50k ive owned the truck. From what ive gathered the xtra qrt. helps keep the input shaft bearing happy on long uphill climbs and generally keeps everything more lubricated.
If i had it my way... I would swap a G56 inplace of my NV. The shift linkage mysteriously came apart in my trans over the summer. I park the truck... come back the next morning, and i my shifter was innoperable. i could find fifth and sometimes reverse....The tranny shop had no explination for what would cause it to come apart the way it did!
Wow wish I would of seen this yesterday. I just put in my new clutch and it would have been a lot cleaner and easier to fill it from the top while it was off. I am not taking that console off right now though. Two of those bolts are a pain.
You can do it from the top bolt of either pto cover too. Don't use non synthetic. It's REALLY bad. Almost cost me a transmission (previous owner put it in- gummed the synchros up so it wouldn't shift) And beware the STOOPID internet wisdom of using motor oil. It will corrode the synchros.
I heard that the factory used the wrong oil and some trannys blew up, I couldn't sort out which was which, and was COMPLETELY paranoid, so I used the GM synchromesh (12345 something or other). Gm used the nv5600, and I was able to verify this with a rebuilder.
Once it was all said and done (more said than done of course) I think any full synthetic advertising to be ok is probably OK. I think what happened with mine, is that the 80w90 that went into it got too hot to survive, and gummed up the little flyweights in the synchros. I looked at them with a bore scope when they were jammed up after shutting down, but didn't learn much. Put the right oil in, and It went from literally impossible to shift when warm, to shifting fine. Took 6 months to get to that point, though.
Actually this whole transmission experience filled me with glee! I bought the truck thinking I was going to have to pull that monster and rebuild it, and at the time, there were hardly any parts available.
A forum community dedicated to Dodge Cummins Diesel truck owners and enthusiasts. Come join the discussion about reviews, drivetrain swaps, turbos, modifications, classifieds, builds, troubleshooting, maintenance, and more!