The tailgate lock on a 2011 HD 2500 that I bought recently does not work. The cylinder is fine, it turns but does not prevent the latch from opening.

Took the cover off last night. I've attached a picture. A metal pin that barely reaches a curved plastic piece which bends very easily when the pin engages. The pin easily slips under the plastic when trying to move into lock position, even after lubing everything down.

There must be something missing (a boot on the pin?) and was wondering if anyone could point it out. Either that or this is the worst lock design I've ever seen. Tried zip ties but they slide off after a few key turns because there is nothing for them to loop through on the cylinder side.

 

It has been a long time since i installed the one on my old 09, but i think that looks right. Also looks like your plastic piece is wallowed out and severly deformed. Mine worked fine for 9 years. In any event it looks like you need some new parts.

 

It may be deformed, but I need a picture or parts diagram to better determine that. It does not show any signs of being wallowed out, the inside edges of the black plastic are clean. The pin apparently is supposed to move a fair bit before engaging either direction. Going to stop at a dealer tomorrow and see if anything can be replaced or ordered that's not a $100+ fix.

 

i don't believe it's a bad design. i also have a 2011 and mine works good and i am usually operating it at least once a week. should be an easy fix.

 

I swapped out the whole inside locking mechanism, not the key cylinder. Turns out the thing should 'snap' from side to side when just enough pressure is put on the plastic piece. I guess time and maybe some of the Line-X overspray had done my in. Parts guy discounted it to $90 + tax.