Gear Box Plug

This probably won't help you now, but for others who haven't yet rounded their plugs it's important to use a modified 6 point socket on these. I believe these are available specifically for this purpose, but I use a standard 6 point socket that I modified myself by grinding down the open side. Sockets have a chamfer inside that helps them slip over nuts & bolts. This is fine for standard nuts/bolts, but since the transmission, transfer case, and differential plugs have so little surface area, this chamfer prevents full contact. By grinding about 1/8" off the open end of the socket you can maximize contact & minimize the risk of rounding off. Tim

PS: Once there is damage here things can get dicey. Carefully applying heat with a torch might help loosen it up. Aluminum expands more than steel, so heating the area around the plug might just do the trick. It's aluminum though, so be careful not to heat it too much! The hammer and chisel method often works too, but if it fails there might not be enough of the plug left for removal via other ways (at least not without getting metal shavings inside the transmission). A good welder with the right equipment can weld a large nut to it, then you can use a socket on the nut to remove. Good luck. Tim