I just wanted to confirm that the rear diff drain plug is supposed to be a 1/2". I'm trying to change some of my fluids, and a 1/2" driver worked on everything but that plug. The 1/2" was too big, but a 3/8" was too small. I'm thinking that it got mashed up good from being dragged over some rocks. Maybe try vice grips? Any other ideas?

Yep, 1/2". You probably will need to clean out the opening with a dremel or a chisel to get the tool in there. It happens.

Thanks, that's what I thought.

Actually its 13.1mm. A pain in the ass to find but a company called facom makes them. It says on it "d105-13.1mm" the 1/2 works for MOST people but if you are having troubles and its starting to round inside the plug this is the RIGHT tool.

Hmm....

After 15 years of working on 'em, still never needed a special tool for that.

13.1?

Couldn't you just squeeze a 13mm on there by pushing really hard?

I just squared mine off a bit with a screwdriver and pounded the 1/2" in there a little. took a couple minutes, but it did the trick

Screwdriver/chisel FTW!