Alternator 12V 37A Part Numbers AL521X, 110529, D3JL10346a, 4748001, D3JL10346A, 680175644669, D3JL10346AB, D3JL10346AB, 8AL2046F, 110529 Overview This 12 volt alternator delivers 37 amps of charging capacity with a negative ground polarity and an external fan for cooling. It is designed for applications that require a spool style mount and a 0.625 inch 15.87 mm shaft outside diameter for pulley fitment. The unit weighs 8.77 lbs 3.99 kg and includes detailed mounting ear dimensions for direct replacement. Key benefits Restores reliable charging performance: 12 volt, 37 amp output supports battery charging and vehicle electrical loads. Designed for direct replacement where spool mount and negative polarity are required: matching mount type and polarity reduces fitment issues. Cooling efficiency: external fan design helps maintain operating temperature under normal load. Accurate mechanical fit: shaft OD and mounting ear measurements provided to ensure correct pulley alignment and secure installation. Specifications Item: Alternator Voltage: 12 volt Amperage: 37 amps Polarity: Negative Fan: External Mount type: Spool Shaft outside diameter (pulley): 0.625 in 15.87 mm Weight: 8.77 lbs 3.99 kg Mounting ear 1 hole: 3/816 threaded Mounting ear 2 hole: 11.3 mm unthreaded Mounting ear 1 thickness: 0.441 in 11.2 mm Why this alternator stands out Fitfocused design: precise shaft diameter and mounting ear specifications reduce the need for modifications and speed up installation. Clear electrical match: 12 volt and 37 amp rating suitable for systems designed around that charging capacity and negative ground wiring. Serviceable installation: common mounting and threaded ear configuration allow use with standard fasteners and mounting hardware. Compatibility and installation notes Intended for systems that require a 12 volt alternator with negative polarity, a spool mount, and a 0.625 in 15.87 mm pulley shaft. Verify existing mounting ear hole types and sizes before ordering: one ear requires a 3/816 threaded fastener, the other accepts an 11.3 mm unthreaded fastener. Confirm pulley fit and alignment using the stated shaft OD to ensure proper belt engagement. Check electrical connectors and wiring harness compatibility as needed for plug and charging circuit connections. Practical use scenarios Replacement alternator for small engine vehicles or utility vehicles that use a 12 volt 37 amp charging system and spool mounting. Service part for fleet or equipment maintenance where quick swap of a likeforlike alternator reduces downtime. or restoration projects where exact mounting dimensions and shaft diameter are required to fit original pulley and bracket geometry. Included part numbers for ordering and cross reference AL521X, 110529, D3JL10346a, 4748001, D3JL10346A, 680175644669, D3JL10346AB, D3JL10346AB, 8AL2046F, 110529 checklist Confirm system voltage is 12 volt Confirm required amperage is 37 amps Verify negative polarity is correct for the vehicle or equipment Measure or confirm pulley shaft OD 0.625 in 15.87 mm Verify mounting ear hole types and sizes match 3/816 threaded and 11.3 mm unthreaded This alternator is a specificationmatched replacement designed to restore charging performance while minimizing fitment surprises.