Problem, short clutch life.

[Don Hoefer <hoefer@cary.eng.pko.dec.com>]

I am about to change my clutch on my 1982 Coupe for the third time. 
My clutches last about 40K to 60K miles.  Wear is not a problem.  The 
diaphragm spring breaks causing incomplete engagement or disengagement 
and increased pedal pressure.  The pressure got so great the second time 
that I broke the clutch pedal.  I have adjusted the cable according to the 
Bentley manual.  It is maxed out to one end of the adjustment range.  I 
have heard of others getting many more miles or years out of a clutch.  
Does anyone have any information about this?  Is this a normal failure 
mode for a clutch or am I just unlucky?  I do mixed city/highway driving.  
I have been driving with my current broken clutch for a year now and 
shifting is becoming a challenge.  (OE and replacement clutches were Sachs.)

                 Don Hoefer
                 hoefer@cary.eng.pko.dec.com