1984 F150

The key can be inserted to unlock the door and 90% of the time, it works, but 10% of the time, the key will rotate approximately 75% of the way and the chrome lock stem inside the truck [don't know the technical name] can be seen trying to pop up, but does not.

I removed the door panel and generously lubricated every moving part I could see and get to. That did not seem to help, so I next purchased genuine Motorcraft lock tumblers and replaced then. Still doing the same. When the driver's door does this, I can go through the passenger door and using the inside door handle, easily open the door.

Help!

 

Possible solution is to replace the linkage and also check to see if the latch assy. is moving freely....somebody jerked hard on the linkage while trying to open will cause it to bend an bind when trying to use the key to open the lock.

 

Thank you, locknkey!

 

I had a problem like this a long time ago...if I had my driver side window rolled down past a certain point, sometimes the door wouldn't unlock even if you opened it from the inside. I think some of the linkage was bent and got bound up.

 

Thank you, TheKirbyMan.