When I worked for FNH, I got sick of replacing clutches on 1710's and 1715's with front end loaders and 4wd. Average lifespan was about 25 hours when used hard . On the other hand, I had it down to about an hour and a half if it had a loader on it to RandR. Split it and you'd see little cords of string that looked like a rat's nest. It was part of the clutch material that would disintergrate. If you cut a hole, find a busing to weld in it that matches the diameter of your hole.
Why would the clutches wear out so fast? Clutch material or crappy design?