AGCO - 4390529M2 - Alternator Multi-Rib Belt Massey Ferguson

This multi-rib belt transmits drive from the engine crankshaft to the alternator pulley, converting rotational motion into electrical charging current for the tractor's electrical system. It sits in the accessory drive loop, tensioned by a dedicated idler or automatic tensioner; the belt's ten internal ribs engage matching grooves on the pulleys to prevent slip under load. A worn or glazed belt produces a squealing noise at idle and reduces alternator output, leading to a gradual battery discharge. The original-manufacturer belt is molded to the same rib profile and pitch length as the factory assembly, so it seats fully in the pulley grooves without requiring shimming or a different tension setting. On replacement, inspect the tensioner and idler bearings for wear and set the static deflection to the value specified for the host engine.