I have had numerous problems with my clutches (yes clutches!).
When my car reached exactly 1 year old it died on the A11 in the middle of the roadworks on a Sunday night with the 'van on the back. Don't asked me how but I managed to get the outfit to this layby which was luckily around 300 yards away (driving it in 1st gear only!).
Anyway the car was towed to a dealer and it was off the road for 4 weeks! as each time I picked the car up the problem was still present (they never tested their work properly
) They even fitted 4 clutches in total even though it was nothing to do with it! Essentially what it was though was a tiny pin hole between the slave and master cylinder hose which was leaking small amounts of fluid hence unable to change gear properly.
This does not directly relate to what you may mean though as its nothing directly to do with clutch life.
However! at just over 2 years old (30k miles) the clutch started to slip badly (I don't have a remap) when I booted it from low revs in top gears. This got progressivly worse as each time it slips it shines the plate surfaces so they get even more slippery! I beleive the slipping to be down to a couple of things
1). Just before it started slippping I purchased a brand new bigger (and heavier) 'van and it would not fit very well into any of the vacant spaces there were at the storage compound, so I spent nearly 1.5hrs to'ing and fro'ing to get see what spaces were big enough. Needless to say the clutch got VERY hot and started smelling. That evening after unhitching the clutch kept sticking evey time I changed gear and so I had a feeling that the clutch was now going to prove problematic from this point on. (I now have a lovely big space to easily reverse it into!).
2). The clutch had already done 25k miles so was already worn!
Suffice to say I had the clutch changed by Veloces with yet another stock clutch. So far its done another 40k miles and its only very slightly beginning to slip in extreme circumstances (like driving like a nutter up a 1:3 slope!). I therefore expect another year out of it so it will have done around 55-60k miles which I don't think is too bad when I think I have towed the 'van to Scotland twice and covered around 15k+ miles of other towing. The 147 to me seems to be a real work horse
and whilst towing does contribute to accelerate wear, it cannot slip just becuase of this as many people on here who don't tow have the same problem too!
Be warned the stock clutches for perfomance diesels, around 110bhp plus (not just Alfa's) are widely reknowned for being weak as they simply cannot handle the torque being transmitted in such small bursts at low revs in high gears. This is due to the mechanical effort to turn the wheels in higher gears is greater than if in lower gears. If the engine has enough torque, the clutch slips and becomes the weakest link.
What was the exact failure with yours then?