Thanks for the great tips, you are right I was thinking of AC TIG welding it, my main concern is that the vw beetle engine and trans castings appear to have a high magnesium content and I am hoping that somone has had some experiance of that material in particular, thanks again.

Has anyone welded a VW Beetle Trans?
I understand from VW forums they are an Aluminium/Magnesium alloy possibly AS21 or AS41.
Any help would be welcome
Thanks