It really depends on the driver and load. I've seen clutches last a few hundred miles, and I've seen them last over 250,000 miles. I'd say you're getting up there in miles for a heavy SUV. Where in the pedal travel does the clutch begin to engage? If it's up near the top, you're likely close to the end. Mine only grabbed in the last inch or so of pedal travel right before it started slipping. After replacement, it now grabs just off the floor.
Here's a quick test: With the vehicle stopped and running, put the transmission in 4th gear. Put your right foot on the brake. Slowly let out the clutch all the way. If you can do this without stalling the engine, the clutch is slipping and may soon fail. If it stalls, you still have good grip. Other than that, there's no good way to tell without pulling the trans and taking a look at the thickness of the lining. Doing it as a preventative measure is up to you, but it's a big job.
98 Amigo, 2.2 5sp 4x4, 4.77 gears and factory LSD.
Power nothing - No power windows, no power locks, no power engine.
Even the hubs are manual now.
2003 Grille and headlight swap