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- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50

Fits:
Porsche 911 Carrera 1984-1989
Click 'Zoom in' for large parts diagram.
Diagram ref no 23
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99919225450
The product you are viewing cross references to these numbers
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50

Fits:
Porsche 911 Carrera 1984-1989
Click 'Zoom in' for large parts diagram.
Diagram ref no 23
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99919225450
The product you are viewing cross references to these numbers
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50

Fits:
Porsche 911 3.2L 1978-89
Click 'Zoom in' for large parts diagram.
Diagram Ref No 35.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90019200550
The product you are viewing cross references to these numbers
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50

Fits:
Porsche 911 3.2L 1978-89
Click 'Zoom in' for large parts diagram.
Diagram Ref No 35.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90019200550
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
Belt size: 10 x 710

Fits:
Porsche 911 1965-73
Porsche 911 Turbo 1976 >>
Porsche 911 SC 1974-79 (Check Size of your Belt)
Porsche 911 SC 1980-83
Porsche 911 3.2L 1984-89
Porsche 914 1970-76
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9991921765A
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
Belt size: 10 x 713 mm
The V-belt runs between the crankshaft pulley and the alternator/fan pulley. It’s the primary mechanical link that spins the alternator to charge the battery and, on air-cooled 911s and 914-6 models, turns the engine cooling fan.
Fits:
Porsche 911 1965 - 1973
Porsche 911 Turbo 1976 >>
Porsche 911 SC 1974 - 1979 (Check Size of your Belt)
Porsche 911 SC 1980 - 1983
Porsche 911 3.2L 1984 - 1989
Porsche 914 1970 - 1976
Please note: Always confirm against the belt size currently fitted and pulley setup before ordering.
Why Replacement Matters - With age and mileage, belts:
• Crack, glaze, or harden, reducing grip
• Stretch, making correct tension impossible
• Begin to slip, causing charging issues and, on air-cooled engines, reduced cooling fan speed
A slipping or failing belt can lead to battery discharge, warning lights, overheating, or being stranded. Fitting a fresh belt restores reliable alternator and fan drive, protecting both the engine and electrical system.
When to Replace - Consider replacing the alternator belt if:
• You see cracks, fraying, glazing, or missing chunks in the belt rubber
• The belt squeals on startup or under load
• The belt has stretched and can’t be tensioned correctly
• You’re doing routine service on a classic 911 / 914-6 or preparing for a long trip
• The car is undergoing engine-out work or restoration
Related reference numbers
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9991921765A
The product you are viewing cross references to these numbers
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50

Belt size: 9.5 x 695
Fits:
Porsche 911 SC 1980-83
Porsche 911 1984-89
Related reference numbers
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9991923135A
The product you are viewing cross references to these numbers
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944 2.7L 8V 1988-89
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944S2 3.0L 16V 1989-91
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
- Porsche 968 3.0L 1992-94
- Porsche 968 Sport 3.0L 1994-95
- Porsche 968 CS 3.0L 1993-95
- Porsche 968 Turbo S 3.0L 1993-94
- Porsche 928 4.5L 1978-82
- Porsche 928S 4.7L 1981-83
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
- Porsche 356B 1959-63
- Porsche 356C 1963-65
Sold each
Fits:
Porsche 356B / 356C - 1960 to 1965
Porsche 911 - 1978 to 1989
Porsche 924S - 1986 to 1988
Porsche 944 - 1985 to 1991
Porsche 968 - 1992 to 1995
Porsche 928 - 1978 to 1995
Related reference numbers
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90007437201
The product you are viewing cross references to these numbers
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
Shim washer for alternator belt pulley 0.5mm for Porsche 911 models, used to fine-tune alternator belt alignment and tension across classic 911 applications from 1965–1989.
What This Product Does
This 0.5mm shim washer sits between the alternator belt pulley halves to adjust pulley spacing, helping to achieve correct belt tension and alignment. Using the appropriate number of shims supports smooth belt operation and reduces the risk of premature belt wear.
Functions
- Spaces the alternator pulley halves to achieve correct belt tension
- Helps align the alternator belt with adjacent pulleys
- Allows fine tolerance adjustment in 0.5mm steps
- Contributes to stable alternator and cooling fan drive
Symptoms of Fault
- Squealing or chirping from the alternator belt area on start-up or under load
- Visible belt slack or difficulty setting correct belt tension
- Uneven belt wear or fraying at the pulley edges
- Traces of belt dust around the alternator and pulley
- Intermittent charging issues linked to belt slip
- Overheating risk on engines where the belt also drives the cooling fan
Why Replacement Matters
Alternator and fan belt systems on classic Porsche 911 models rely on a stack of correctly sized shims to set belt tension within specified tolerances. Missing, damaged, or incorrect shims can make precise adjustment difficult, leading to belt slip, noise, and accelerated wear. Replacing worn or lost shim washers when servicing the belt or pulleys helps restore proper alignment and tension control, supporting reliable charging and cooling operation on older 911 engines.
Fits
- Porsche 911 & 912 (1965–1989)
- Porsche 911 1974–1977 2.7L / 1976–1977 3.0 Carrera
- Porsche 911 1975–1977 3.0L Turbo (930)
- Porsche 911 1978–1983 3.0L SC
- Porsche 911 1984–1986 3.2L
- Porsche 911 1987–1989 3.2L G50
FAQs
- Q: How many shims should be used?
A: Follow the Porsche workshop manual for your specific model. The total number of shims is usually fixed, with the split between in-use and parked shims determining belt tension. - Q: Where are the spare shims stored?
A: Typically, unused shims are kept under the pulley nut or outer pulley half so they remain available for future adjustment. - Q: When should shims be renewed?
A: Replace shims that are bent, corroded, damaged, or missing when changing the alternator belt or pulley components, to ensure accurate tolerance adjustment.
Support & Advice
Ensure you use the correct combination of shims to bring the belt tension within the recommended tolerances for your engine. Always confirm fitment against your vehicle details (model, year, engine) before installation.
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9301065640Y
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Engine Rebuild Belts, Tensioners & Rollers – Precision Timing for Reliable Porsche Performance
Engine rebuild belts, tensioners, and rollers are essential components in maintaining your Porsche’s precise engine timing and smooth operation. These parts work together to synchronise the camshaft and crankshaft, ensuring valves open and close at exactly the right time for optimal combustion. Over time, these components can wear or deteriorate, especially under high performance or extended use, making replacement vital during an engine rebuild or major service.
At Design911, we supply a full range of genuine and high-quality belts, tensioners, and rollers for various Porsche models including, 911, Boxster, Cayman, Cayenne, Macan, and Panamera models. Each component is designed for strength, accuracy, and long-lasting reliability — ensuring your rebuilt Porsche engine performs flawlessly mile after mile.
What Do Engine Belts, Tensioners & Rollers Do?
These components form the heart of the engine’s timing and
auxiliary systems. They:
- Drive
key engine components, including the camshaft, alternator, and water
pump.
- Maintain
accurate timing for optimal combustion and efficiency.
- Reduce
friction and noise through smooth roller and tensioner operation.
- Ensure consistent belt tension to prevent slippage or premature wear.
Together, they guarantee your Porsche’s engine runs smoothly, efficiently, and reliably — whether cruising or driving at peak performance.
Why Do Belts, Tensioners & Rollers Fail?
Exposure to high temperatures, vibration, and constant
motion causes natural wear over time. Common causes of failure include:
- Aging
rubber belts becoming brittle or cracked.
- Worn
bearings in rollers or tensioners leading to noise or vibration.
- Loss
of tension causing belt slippage or timing misalignment.
- Contamination
from oil or coolant degrading materials.
- Extended maintenance intervals leading to unexpected failure.
Symptoms of failing components include squealing noises, poor engine performance, rough idle, or even timing belt failure, which can cause severe engine damage if ignored.
Why Replace Belts, Tensioners & Rollers During an Engine Rebuild?
Replacing these components during an engine rebuild ensures long-term reliability and eliminates the risk of future timing-related failures. A fresh set of belts, rollers, and tensioners restores precision, efficiency, and performance — protecting your investment.
Benefits of replacement include:
- Restored precise timing and smooth operation.
- Reduced risk of catastrophic engine failure.
- Enhanced reliability and longevity of the rebuild.
- Quieter, more efficient engine performance.
All components available from Design911 are made using premium-grade materials, precision bearings, and advanced heat-resistant compounds, ensuring maximum durability and performance in high-stress Porsche engines.