Transfer case np203

[77 stepside]

I can't get a ansewer to my question from anyone here. Maybe you guy's can help. I have a 77 half ton step side with a 350tubo with a np 203 transfercase. All I would like to know is what kind of fluid it takes. I have gotten ansewer's from 10w-30, 80-90w gear oil, and atf tranny fluid.

Does anyone have the right ansewer ?

Thank you .

[wyldman]

It takes motor oil.I have always used synthetic 10W30.For the smal amount it takes,and for the amount it gets changed,the extra cost of synthetic is worth it.

I think the original spec was 10W40,but the 10W30 seems to work just fine,and it's what most people seem to use.The slightly lighter weight makes it easier to shift in the cold.

[77 stepside]

Thank you for that info.

[77 stepside]

Whoops, hit the wrong key, sorry.

[76chevyman]

Does that go for the NP205 as well because im running 80-90 in it right now and seeing this im woundering should i change it. it hasnt giving me any problems but you cant hurt that tranfercase anyway. so what should i run in my NP205?? much thanks

Rich:burnout

[wyldman]

The 205 uses 80W90 gear oil,so yours is filled correctly.

Just in case anyone else asks,the NP208 uses ATF. :D

[76chevyman]

Thank you o mide auto god LOL much thanks man

Rich:burnout