Differential drain plug size

[Adambul]

Hi all,

Just changing my diff oil and the drain plug appears to be very tight and an unusual size. Any idea what size so I dont end up rounding it off. Its smaller than 13mm but bigger than 12mm and a standard 1/2" socket still feels too big. Any ideas so I can get the exact size socket to avoid damageing what appears to be avery tight nut!?

[Adambul]

Fast by Fred said:

Here's My Diff Story
(2001 4.5 HW)
HTH

Wow, no wonder im having trouble. The fill nut came off very easy for me the drain plug however is a different matter. I don’t have access to a welder so will have to get creative. Mine is smaller than 13mm but larger than 12mm so very odd size!

[Adambul]

I think mine is 1/2" as suggested above but it is so tight and with a star socket is in danger of being rounded off with my efforts! I've just ordered another flat faced socket and if that doesn't work it will be exhaust off and stilsons out!