First, I discovered a new way to create a problem: I cleaned and rebuilt the ramp up/down assembly at the same time I was cleaning/rebuilding some other assemblies and accidentally swapped plungers with another assembly. The (incorrect) plunger now in my "up" assembly was a little shorter (2" or 2 1/8"), which means the ramp up action will try to extend the ramp even higher, causing it to bind. I figured out my mistake and put the right plunger back in and that fixed the binding in the "up" position...for about 2 games.
It's basically still binding/overextending. If I manually push the bar under the ramp to the left a bit after it's raised, then firing the down solenoid will lower the ramp. But the next time it goes up, it binds stuck high.
I've been reading as much as I can find about this on pinside and other sites and saw some people talk about making adjustments to the mechanism on the bottom of the playfield. I can't find any adjustments there. The only adjustment I'm aware of is the position of the ramp bar on the actuator arm. I've played with it to no effect (it's currently set to the lowest position since it seems like that would cause the least binding).
I removed all the previous grease/gunk, so the mechanism is clean and loose...maybe too loose? There seems to be more lateral play than I'd expect. But it worked fine before I cleaned and "fixed" it ( ) so I don't think that's it. Any suggestions?