I'm gonna swap out the oil... what should I run? (winter is coming)

 

from what I understand there is no best. There is only one kind thats approved to run in the 4500. castrol Syntorq® LT 75w85w. If you call castrol they will say only dodge can sell it to you. However I found it here http://www.quad4x4.com/NV4500%20Parts.htm for less then half the price of the dealer. Now I'm sure others will say you can run this or that and that they've done it for a while and its great. I'm not saying you cant run something else only that this syntorq stuff is the only factory approved oil so its what I use. Hope this helps you out some.

 

GM also carries it, sometimes cheaper tha Dodge. It was cheaper by a lot at the Dodge dealer when I bought mine.

And yes, the SynTorque is the only approved fluid.

 

Using anything other than Syntorq (not Syntech) may get you by for a while but will come back to bite you in the rear 100k down the road no matter what the salesmen and people who have used brand X for ten thousand miles tell you.
Other oils are not compatible with the syncros and actually dissolve them over time.

 

Syntorq.
All the way.
Got 253k miles on the stock nv4500
Still never gave up to the ghost, just became hard to shift, but still shifted when I pulled it(just was hard in 2nd, reverse)

 

That's what they say syntorque all the way but I've had very good luck with the AMSOIL tranny lube, except for that pesky 5th gear nut!

 

So if you had your tranny rebuilt and used the brass syncro's you can use whatever oil you want?