Did the grub screw up so it was sticking out into the receiver by about 5mm , then dropped it onto the ball, of course it wouldn't lock down so I just backed out the grub screw a bit untill the hitch dropped onto the ball properly and the lock engaged, and did up the locknut .
When we got home today and I unhitched the van it still stuck a bit ,but not as badly as before.
I think the trail-a-mate jack/jockey wheel that I've ordered should help a lot too
