However, when using a jack to lower the king pin it always runs the risk of it kicking out.
Did it once and ran out of drop on the jack. Quite challenging as I therefore did not have a jack to raise the car to get it out.
That must have been a bit of an embuggerance! Yes, two jacks are always handy. I've got a couple of little ones suitable for the Morgan, and a bloody great 3-ton jobbie I use for the Land Rover and the Tractor. The biggun will lift anything, but is so flipping heavy that It's a complete pain if you have to move it anywhere, it's almost too heavy to pick up.