Thanks for the idea should b able to knock that out Tom after work unless I come up with something else tonight

 

5/16" is correct, I sacraficed an old 3/8" extension and on a bench grinder took a bit off all 4 sides. I used a 5/16" wrench to guage my grinding. When it fit snug both ways your good to go. There is room to add another short extension and a wratchet. If you don't want to go through that, the 5/16" stock idea with a vise grip looks like a winner. Use teflon tape when you replace it.

 

Thats kinda annoying, but great to know.

 

Check out CTA Automotive Specialty Tools #2049 3/8" drive square head drain plug socket set 8mm & 10mm (5/16" is almost exactly 8mm). They also offer a 8mmx10mm square head wrench #2577.

 

^^Thanks for the info.