What year truck? Are you still within 6 year rust warranty???
By door jambs, where exactly do you mean? I have a 1998 D1 and had problems with rear door "c" pillar, in other words the framing on the body at the back of rear doors. It was the black-painted part just above where the rear wheel arch intrudes to the door opening. I had it fixed by the dealer right at the end of the warranty.