1968 Rockwell T221 silly question

[vectorit]

Hey all, I am just curious what the best process is to drain the old oil out of a T221 while it is still in the truck?

I am always adding oil, since it leaks like any other T221. But the oil drips are black as can be, which makes me want to try to flush out the old oil and add all new lubricant.

On the drivers side, there are two plugs. The highest one is the one I use to add oil, and I guess I could pull the lower one to drain but it is not at the lowest point of the T case. So I am pretty sure not all the dirty lubricant would be drained...

Also, what's your favorite lube to use in the T221? I have always used the general purpose lube the manual recommends, but just wondering if there is something better out there?

I have been tempted to use a heavier grade, since now I am in the summer months. The garage temps alone get over 100 degrees, and my Rockwell and Eaton axle weep oil just sitting in the garage. While driving in the heat it gets pretty messy, so I'm wondering if a heavier viscosity will reduce all that mess? Or is it even worth it?