95 Dakota with manual locks. Drivers door lock works hard..spray wd-40 in lock..works fine for a couple days then acts up again. Any ideas?

 

Dirt built up. Bent or broken parts. Hard to tell unless you open it up and take a look.

 

I'd go with dirt build up, use some carb/brake/electrical cleaner whatever's handy and spray everything down then recoat everything with graphite.

The reason WD40 works for a few days is because it's mostly solvents with a small amount of lubricant, it dries up fairly quickly then you're right back where you started the graphite will be there for a good while.