All great information. Thak you all for your input.

I use the 80 weight oil in there too.
I like the gasket with goo. Doesn't require nearly as much goo and makes pulling it off a lot easier. And at less than I spend on an oil filter, I can get one for each dif! Too easy.

Sunder,
I will be taking my 91 YJ to the beach for about a week for driving on the sand, some dunes and lots of fishing! I cary an air compressor with me so putting air back isn't an issue, but for 31x10.50's on stock rims, how low can I go on the air pressure? I run at 30/32 r/f on the road, 35/35 on the open highway and used to drop down to 15/20 for the sand with 235's... any suggestions?