13mm square socket for Subaru rear differential

[mattthemuppet]

funny you say that, I was trying to get the CVT fill plug out and the only 10mm male socket I had was a 1/4in drive and I don't have a 1/4in breaker bar. Fitted a 3/8>1/4 adapter so I could use my 3/8in bar and the bar started turning without the socket moving. This sent me into "alarm, rounding plug mode", firing up the MAP torch and freeze spray to shock it loose. Tried again and the same problem, but when I looked closely I realised that the male 1/4in part of the adapter was slowly shearing off.

got out my 10mm allen key and a piece of pipe to fit over it for extra leverage and it came off with the 1st tug!