Happijac failed while driving down the interstate!

Thanks again for coming back so promptly.My truck is a Landrover Defender crew cab 130. The camper doesn't mention a model number, Just Adventure.manufactured by Caravans Unlimited Inc in the USA The weight is1450 lbs. I don't have a font/rear weight, but whatever it is it should be well within the capability of the Acme screw. Both my failures have been on the front.