Hi
I have an NP231 transfer case that is almost half empty on fluid. I have some Mercon V ATF fluid, can I put that in it or do I need something else?
I found this on jeep forum

Transfer Case

-NV231 Part-Time (Command-Trac) - 2.2 Pints (1.0L) Dexron III/Mercon

Is mercon v similar enough to mercon? What do you guys put in your 231s?

On a side note, if anyone has any tips on stopping a leak from the drain plug on the 231 it would be greatly appreciated.

Are you sure it's leaking from the threads? You could try some thick PTFE tape on the threads (dont buy the crappy $0.99 tape, it sucks. Get the better stuff, I use Blue Monster or FastTape). Just make sure you wrap the tape in the ​​same direction as the threads.

For fluid, the t-case doesn't care too much but I wouldn't mix random fluids. Just pull the drain plug, wrap the threads, and fill it up with fresh fluid. I use Supertech ATF+4, but you can use Dex3/Merc (Valvoline MaxLife is really good), or whatever else you want.

I think the Merc III is recommended...but honestly I think most just do it at the same time as the trans service and use the same fluid they're using for it.

Thanks for the help. I flushed it and the teflon tape sealed the leak!