Latch removed from door, Anti-slam pin pushed in fully, latch intermittently binds/won't open or close (as if anti-slam wasn't pressed). Looks like equivalent of your 82-239. Latch was replaced ~ 3 months ago (part likely from Home Depot/Lowe's), are there adjustments or lubrication needed? Is there a way to disable the anti-slam?
Dave Sr. from SWISCO responded:
August 15, 2017
I would try lubricating the old lock first with silicone spray, or even grease. If that doesn't help get it working properly again, then I think it's time to just replace the mortise lock entirely.