Welded upper balljoint.

if you are daft like me....you can press the arm... if the arm can be supported under the balljoint hole and you have an appropriate inverted cone shaped foot for your press you can erm, how do i put this.... re shape the hole slighty once a considerable pressure is applied..... you may have to TAP the balljoints in up to the start of the thread.....don't go too mad. tried it went too far could get anything in....went with better set of arms.... every day is a school day :) we used some part of a press tool that the engineering shop had for stamping depressions into thick sheet. it was proabbly made in 1930, probably won't try again... But is a possible solution

you could probably achive the same by hitting it with a FB hammer right on the rim but that seemed medieval by comparison, local blacksmith or forge may be able to help if getting "Medieval on Its ***" suits the situation.

Dave