Restoring the wiper system on a Porsche 356 requires careful attention to the motor and its associated parts. Whether you are dealing with a slow-moving wiper, a motor that no longer runs, or simply want to refresh the system before a show, understanding the available parts and how to choose them is essential. This guide covers the key components, compatibility considerations, and practical advice for sourcing and replacing wiper motor parts for the Porsche 356.
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Understanding the Porsche 356 Wiper System
The Porsche 356 used a single-speed or two-speed wiper motor depending on the model year. Early cars (Pre-A and early A models) typically had a single-speed motor, while later A, B, and C models often featured a two-speed system with a self-parking function. The motor is mounted under the cowl panel, connected to the wiper linkage and transmission. Common parts that may need replacement include the motor itself, the gearbox or reduction gear, the park switch, the brush holder, armature, and the wiring harness grommet. The system also includes the wiper arms, blades, and the pivot shaft assemblies, but the motor is the heart of the operation.
Original vs. Reproduction Parts
When restoring a Porsche 356, you have two main sources: original factory parts (N.O.S. – New Old Stock) and modern reproduction parts. Original parts are prized for authenticity but can be expensive and difficult to find. Reproduction parts are more readily available and often improved in terms of materials and reliability. However, not all reproductions match the exact appearance or performance of originals. For a concours-level restoration, original or period-correct parts are often preferred. For a driver-quality car, high-quality reproductions are a practical choice.
Key Original Part Numbers
Original wiper motor part numbers vary by model year. For example, early 356s (1950-1954) used a Bosch 6V motor with part number 0 390 101 001 or similar. Later 12V motors (356B and 356C) have different part numbers. The associated gearbox assembly also has separate part numbers. When searching for original parts, it helps to cross-reference your specific chassis number.
Reproduction Quality
Reproduction wiper motors and rebuild kits are available from several classic Porsche parts specialists. Most reproductions are made to match the original dimensions and electrical specifications. Some even include a built-in park function that works reliably. The quality of reproduction parts can vary, so it is wise to buy from a reputable supplier known for Porsche parts. Look for parts that use brass or steel gears rather than plastic, as plastic gears wear out faster.
Common Wear Items
The wiper motor in a Porsche 356 is over 50 years old on even the newest examples. Components that commonly fail include:
- Carbon brushes: The brushes wear down over time, causing intermittent operation or total failure. Brush replacements are inexpensive and easy to install.
- Armature: The armature's commutator can wear or develop shorts. It can sometimes be cleaned or turned on a lathe, but replacement is often simpler.
- Park switch: Older park switches often have corroded contacts. A faulty park switch can cause the wipers to stop in random positions.
- Gears: The worm gear and idler gear inside the gearbox can strip or wear smooth. Replacement gears are available in both original and repro materials.
- Bearings: Dry or worn bearings can cause the motor to run slowly or noisily. Some bearing sizes are standard, but others are unique to the 356.
- Wiring and connectors: The wiring harness that connects the motor to the switch and power supply can become brittle. Replacement pigtails and grommets are available.
Where to Source Parts
Avoid general online marketplaces for price comparisons, but do note that specialized Porsche restoration shops are the best source. Suppliers like Stoddard, Pelican Parts, and Classic Fabrication offer many 356 wiper motor parts. Also consider Bosch classic parts suppliers, as Bosch was the original equipment manufacturer. For N.O.S. parts, check swap meets, Porsche club classifieds, and specialist dealers. Be prepared to pay a premium for original parts.
Rebuild Kits
Several vendors offer rebuild kits that include brushes, springs, gaskets, and sometimes the park switch. These are a cost-effective way to restore your original motor. Make sure the kit is specifically for your motor's voltage (6V or 12V) and model year.
Complete Replacement Motors
If your motor is beyond repair, complete replacement motors are available. Some are exact reproductions of the Bosch units, while others are modern replacements that fit in the same location. When buying a complete motor, check that it includes the gearbox assembly and that the mounting holes and linkage attachment points match your car.
Compatibility Notes
Porsche 356 wiper motors are not all interchangeable. The biggest difference is voltage: early cars used 6V, later cars 12V. If you are converting a 6V car to 12V, you will need a 12V motor or a resistor/voltage reducer. Also, the direction of rotation and park switch orientation can vary. The linkage attachment is generally the same for all 356 models, but the length of the motor shaft and the position of the park switch may differ. Always compare your original motor to the replacement before buying.
Rebuilding vs. Replacing
If your original motor is seized or has an open winding, replacement might be necessary. However, many 356 wiper motors can be rebuilt. Rebuilding preserves the original date codes and appearance, which is important for authenticity. The cost of a rebuild kit is usually under $50, and the labor is moderate if you are comfortable with electrical work. If you have no experience with electric motors, consider sending your motor to a specialist for rebuilding. Replacement motors cost $200 to $600, depending on originality.
Installation Tips
Replacing or rebuilding the wiper motor is a straightforward job on the 356, but there are a few tips:
- Disconnect the battery before working on any electrical components.
- Remove the glove box and the cowl grille to access the motor.
- Mark the position of the wiper arms before removal to make alignment easier.
- When reinstalling the motor, ensure the park switch is adjusted so the wipers stop at the bottom of the windshield.
- Use dielectric grease on the electrical connectors to prevent corrosion.
- Check the operation before reassembling the cowl.
Final Recommendation
For a typical driver restoration, the best approach is to rebuild your original motor with a quality rebuild kit. This is cost effective and maintains the car's character. If your motor is too far gone, invest in a high-quality reproduction motor from a reputable Porsche parts house. Avoid cheap generic motors that may require modifications to fit. Always purchase parts that match your car's voltage and year. With the right components and careful installation, your 356's wiper system will function reliably for years to come.