Sticky door latch...

I know I'm replying to a very old thread but, I am reading it because I needed some of this information. That said, a former locksmith with whom I go to church says the best lube for locks and latches is Tri-Flow.

 

I have a 2004 Peterbilt 379 my drivers door won’t unlatch from the outside or the inside got the door panel off all the rods are in place but it still won’t unlatch anybody have any ideas I’m at my wits end

 

I Prefer graphite lube like slip plate or a homebrew. Oils are just asking for future headaches.

 

old thread but I had same issue with my 06 379, it’s not really a lubricant issue for all. Older guy retired driver took a piece of sandpaper and got in between the mechanisms, then applied some lithium grease and no more problems. I have been fighting the issue for years and even put in new mechanism to no avail. No problem since he did that!