Is there 80-90w oil needed in the front of the drivetrain, like the rear, or is it just the transfer case to worry about with some 10w30?

Transfer case calls for 5w30 oil. Using 10w30 might be a little on the heavy side during winter.

Roger that, I thought maybe because I'm in Az, I'd go 10 (plus, I had it on my shelf) but I'll go 5 unless you tell me otherwise. How about the 90 weight, does it just go in the back hogshead, or is there a filler plug for it "up front", as well. Thankyou.

Not sure about 80w90 in the front. If you had access to an owner's manual that would be helpful. Perhaps you could download one or purchase one from www.helminc.com

I'll just find out when I crawl under there (which you've saved me from long enough, Thankyou). Nothing in the "Haynes" or the owner's manual. 281,000 on the clock with the transfer case oil ignored for quite some time (61,000 +).