043-903-109 VW Generator / Alternator Pulley 12V - Black

Generator/Alternator Pulley Set (Inner & Outer) – 043-903-109

The 043-903-109 is a complete generator and alternator pulley kit, including both the inner and outer halves. This set is a direct replacement for 12-volt air-cooled Volkswagen engines. Because the cooling fan is driven by the same shaft as the charging system, the integrity of these pulleys is paramount. A failing pulley set can lead to belt slippage, which causes immediate engine overheating and battery drainage.

These halves are manufactured from heavy-gauge stamped steel to resist warping and "egging out" at the center mounting point. When paired with the correct number of shims, these two halves sandwich the V-belt to provide the specific tension required for efficient cooling and charging. Replacing both halves together ensures perfectly matched mating surfaces, which prevents premature belt wear and protects the alternator or generator bearings from vibration.

Detailed Vehicle Compatibility

VW Beetle:

• 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977

VW Super Beetle:

• 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979

VW Karmann Ghia:

• 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974

VW Thing:

• 1973, 1974

VW Transporter (Bus):

• 1967, 1968, 1969, 1970, 1971

Product Highlights & Features

• Complete Two-Piece Set: Includes both the inner and outer pulley halves to ensure a perfectly matched belt channel.

• Heavy-Duty Stamped Steel: Designed to withstand high RPMs and the thermal stress of the engine bay without flexing.

• 12V System Specification: Sized for the standard 12-volt charging systems used in late-model air-cooled Volkswagens.

• OEM Fitment: Precision-engineered keyway ensures a secure lock to the generator or alternator shaft.

Technical Specifications

• Part Number: 043-903-109

• Material: Stamped Steel

• Components: Inner Half and Outer Half

• Belt Type: 9.5 x 905mm or 10 x 905mm V-Belt

Installation & Maintenance Tips

• Proper Adjustment Procedure: To properly adjust the belt, you absolutely must start with the belt too loose and remove 1-2 shims at a time until the correct tension is achieved.

• Avoid "Tight Enough" Shortcuts: If you remove too many shims, you will wind up tightening the nut until the belt feels tight, but the two pulley halves are not actually squeezed together. As the engine rotates, the pulleys will wear one another out.

• Preventing Pulley Ruin: By doing it the 1-2 shim way, when you get the right tension, the pulley halves are tight against the shims and one another. This prevents the outer pulley from moving out at the top and in at the bottom during every rotation, which is what typically ruins them.

• Shim Management: Store any unused shims on the outside of the outer pulley half, under the nut and washer. Never discard them, as you will need them when the belt stretches or when you install a new belt.

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