The problem is that both the latch mechanisms and the striker plates on my doors are extremely worn out. A few years ago I welded in new material where the old metal on the striker plate was worn out, but that too has worn out. Yes, everything is adjusted as well as it can be, but the striker plate is so worn out that it won't hold the door very well. The mechanism also is so old that it doesn't spring back well and looses its holding ability over bumpy roads. The whole thing is just too darn old and needs a complete rebuild.

I'll check Jim Carter. Thanks.