"what was the worst problem you had with your tm?"
anything that causes major down time, Scott
most anything and everything can be replaced/repaired in a day, (if you're able to spin a wrench) but waiting for parts if none available locally can be the pits
Not unlike your car or service van, stuff wears out/fails with miles/age and needs to be repaired/replaced at times.
be it brakes, shocks, ball joints, fuel pumps, trannys etc.
Same with TMs.
The more hours, the more things wear and are prone to failure
Depends on the TM, but "in general" the most expensive components are engine, blower and pump .
Fortunately, "in general" those are pretty durable if maintained well
..L.T.A.