Throw out bearings...

[humdingerslammer]

Might b something not right with prior installation. Zip ties? WTF?

The clutch slave and clutch master cylinders r usually self bleeding of air so not the likely culprit. Is there a leak in clutch line somewhere. Any problems with reservoir level? Is the Pilot bearing OK?

[layback40]

(192,000km & the clutch has failed again. It had a slight vibration/pulsation for a while, but the failure was between starting off from the lights, and changing into 2nd.)

Wow 192000km on a manual clutch... that's amazing. I have best got about 150000km out of mine (changed earlier than this since everything apart for some reason or other and preventative maintenance that prevents me being stranded in the bush. The Wrangler manual 3.8L is well known for rattle that is due to worn pivot bolt and selector gate. Best change them when changing clutch.

I have had 2 DF Centreforce clutches that have not looked anything like the pictures you posted at change over... just worn friction plate etc. Perhaps wasn't aligned properly at instalment.
)
I would send photos to Centreforce (address from its website) sales@centerforce.com to see what they have to say...

I replaced the clutch in my XJ diesel (not long after I got it) at 140,000km. Gearbox out for RMS replacement. Its now at 365,000km, and no sign of needing replacement. So, 225,000km & going strong. I can remember as a child, my parents replaced the clutch in their XK Falcon at 100,000miles (160,000km). Suspect that there maybe a bit of resting ones foot on the clutch peddle maybe causing reduced life. Used to be the problem years ago.

[Banshee]

Might b something not right with prior installation. Zip ties? WTF?

The clutch slave and clutch master cylinders r usually self bleeding of air so not the likely culprit. Is there a leak in clutch line somewhere. Any problems with reservoir level? Is the Pilot bearing OK?

When you break the retention clips on electrical connectors, then use zip ties to hold them together instead.

I have a few like that around the place, damned cheap plastic connectors hardening under the bonnet. They often break the first time you try to depress the clip to remove it.