A couple of weeks ago this happened
The drivers side just parked itself in an upright position. I thought, bless her, she just wants more attention from me.
David Aikegate helped out with is reply;
I've just repaired ours after it did the very same thing, doh.
I got the uprated system from Mike Satur. You can drill through the ball joint and fit a nut and bolt, or temporarily use a hot soldering iron to melt the palstic cup around the ball.
It was the
hot bit of David's reply which got me thinking.
I cleaned up the end of the arm with the socket on, then using a silicone spray carefully coated the ball at the end of the the other arm and reassembled the wiper mechanism.
I then used a hot glue gun to apply glue generously to the assembled joint.
The silicone coating on the ball stopped the glue adhering to to the ball but allowed it to form around it and all over the socket end to make a plastic housing which has, to date, kept everything in place.
It has had quite a lot of use over the past weeks and on inspecting it today the whole arrangement is very secure and works perfectly. It looks a bit crude but to be honest in the normal parked position you don't actually see it.
Obviously only time will tell but the fix was done in five mins and in principle should stop the two arms from popping apart.