ATF or motor oil in AW-4

[Rubikahn]

Getting ready to change fluid, pinion seal, and rear diff cover soon. I’ve read that the recommended fluid to use in the 231 tc is ATF, but I’ve also seen 5W-30 Dino/synthetic motor oil mentioned. Anyone have any experience running 5W-30 in their 231?  According to Novak Adapters some of their customers have run it with good results.

[MiNi Beast]

Honestly run what ever you have available at that affordable price. Just gears let em grind and work. I have always used and abused my 231s with atf and typically change it once in a while playing in water, otherwise keep it full and run it. No worries. 

[PIKE]

If money is no object,

 

 

https://www.redlineoil.com/racing-atf-type-f

 

[cruiser54]

Dex/Merc ATF in both the transfer case and the AW4 trans. 

[Rubikahn]

Thanks guys, decided to go with the ATF. I picked up two quarts of ATF-4 at Walmart this morning. 

[AZJeff]

2 hours ago, Rubikahn said:

Thanks guys, decided to go with the ATF. I picked up two quarts of ATF-4 at Walmart this morning. 

I assume you meant "ATF +4" in your statement above.  That will work just fine in your transfer case, but DO NOT use it in your transmission if it is an AW-4 automatic.    For those, use what Cruiser recommended above.

[derf]

Yeah, for the automatic, make sure you run the appropriate auto trans fluid.  It's not all the same and it matters what goes in.

 

Put the same stuff in the NP231.  That's a little more flexible in what it can take but if you run the same in the trans and t-case it's easier to keep track of.

[Rubikahn]

So, I returned the two quarts I’d originally bought and grabbed a gallon of the Dex/Merc Cruiser54 suggested. Gonna do the trans at the same time. 

[ghetdjc320]

I ran straight 30 weight conventional oil in my 231. Had very good results. That was in the tropics though with consistent high temps year round. It did quiet down the case a bit over atf. Worked great for me