Thanks Bill. The door seals are new but we have checked the fit for interferance and that's good. The cab mounts are good and have all been adjusted. The latch in the door is new from Brothers, we even put the old latch back in to try. The striker is tight and we marked it when the door was closing good and it doe's not move.
We can get it to close good and it may last for a week or 2 and then acts up sometimes while just sitting in the shop for a period of time.
Any other thoughts suggestions??