My first one (slave cylinder) went @ 38K, ruining the clutch & pressure plate w/ it. Cost me $800 2K out of warranty. I'm still about 3/4 pissed off over that. On my second one (just rolled 80K), but i'm starting to get that feeling. I pulled the inspection grommet, and it's dry as gunpowder, but my gut tells me things are about to go wrong in there.
The clutch will last a long time if you don't abuse it. On Rangers, the slave cylinder is the limiting factor.