I understand the 332 on its introduction, used the same main rotor gearbox as the RAF's HC1 model. The HC1s were not fitted with a torquemeter and limited to 15.5 degrees Collective Pitch for takeoff and hover in temperate climates, with further restrictions in other phases of flight. We seldom had MRG problems (or engine problems with the old Turmo IIIC4, for that matter).
I was informed that the 332s were flying using the equivalent of 16 and 16.5 degrees CP. On hearing this I assumed that the gearboxes were modified to take extra power. We later heard that they weren't.... if that's true perhaps it's not surprising that there were some reliability issues.