Freewheel Clutch/Pulley for alternator. This unit is standard equipment on all Sprinter alternators. THIS IS A CRITICAL COMPONENT OF THE SERPENTINE BELT SYSTEM AND A KNOWN CAUSE OF BREAKAGE PROBLEMS
IT IS COMMON FOR THIS DECLUTCHING PULLEY TO FAIL, LONG BEFORE THE ALTERNATOR WEARS OUT. A special tool is required for installation of this unit and are not usually replaceable outside a repair facility.
If you are purchasing a new alternator, you will not need to buy this, as the alternator is furnished with a new pulley.
Sprinter II 2007-2018 3.0L V6
This is the identical OEM pulley sold at a franchise Dodge, Freightliner or Mercedes dealer.
Fits all Valeo alternators...180 and 220 Amp
If you have had problems with snapped serpentine belts or a broken belt
tensioner arm or roller, this declutching pulley has most likely
failed. When operating correctly, this unit has a one-way clutch to
minimize belt flutter and therefore, stress. Over time, this pulley will seize, thereby
losing its one-way decoupling action. To check the integrity of your
alternator pulley, simply remove the belt and place a screwdriver into
the front of the alternator cooling fan to stop the armature from
rotating. Then turn the pulley by hand. If it moves one direction but,
not the other, it is functional. If it will not rotate at all, it has
Video demonstration of why this device is a critical component: