Tailgate will not lock

[KurtisWalton]

I have a 2011 3500 SRW Megacab Outdoorsman. The tailgate lock no longer works. I have cleaned and lubricated the latches. The key part still turns but I am unable to lock it. This is a manual lock. I have had no problems with the tailgate opening on its own. I just am not able to get it to lock. Any ideas? Thanks.

 

[Wiredawg]

is there an access plate on the back of the tailgate to get to the back of the lock? Sounds like the locking tab is loose, bent or has come off.

Cheers, Ron