cab. Was driving last week and the door flew open. Thought the actuator had gone bad, so replace it. Simple job. But it won't latch. It appears to be lined up with the post on the quad. but when i try to shut it, it will not latch. Both the old and new actuator will latch when push on the u latch post when not in the door. I have checked the hinges, no excessive movement. I am stuck! Help!

 

Back off each bolt that holds the latch in 1/8th of turn, try the door, doesn't latch? Go another 1/8th. Chances are good, before you get a half turn on it, it will latch.

Cleaning it out really good, (brake cleaner, or carb cleaner) and then spraying it with some white lithium grease will help as well.