NATIONAL 226520 Rear Engine Seal 65-77 2.0L 2.2L 2.3L 2.4L 2.7L-H6

( Brand: National ), ( Manufacturer Part Number: 226520 ), ( Part Type: Seal Engine ), ( Placement On Vehicle: Rear )

Review NATIONAL Rear Engine Main Seal 65-77 Porsche 2.0l 2.2l 2.3l 2.4l 2.7l-h6

The **National 226520 Rear Engine Seal** is a precision-engineered, high-performance gasket designed exclusively for Porsche 911 models equipped with the **2.0L, 2.2L, 2.3L, 2.4L, and 2.7L (H6) air-cooled engines** produced between **1965 and 1977**. This critical component serves as the vital barrier between the rear engine compartment and the transmission housing, ensuring optimal sealing to prevent oil leaks, contamination, and excessive heat transfer all of which are critical for maintaining the longevity and reliability of your classic Porsche s drivetrain.

Crafted from **high-temperature-resistant rubber compound**, this seal is engineered to withstand the demanding thermal and mechanical stresses inherent in Porsche s legendary air-cooled engines. The material is formulated to resist oil, fuel, and coolant degradation over time, providing long-lasting durability even under high-performance driving conditions. The seal s **reinforced construction** ensures a tight, consistent fit across the rear engine housing, minimizing the risk of warping or premature failure a common issue in older Porsche models where gaskets can degrade due to age or improper installation.

One of the standout features of the **National 226520** is its **universal compatibility** with the specified engine variants, making it an ideal choice for restorers, enthusiasts, and mechanics working on classic Porsche 911s. The seal is designed to fit seamlessly within the engine bay s tight confines, adhering perfectly to the rear oil pan and transmission interface without requiring excessive modification. This precision fitment reduces the risk of misalignment, which can lead to leaks or damage to surrounding components.

Beyond its functional reliability, this seal is also a testament to **National s commitment to quality and heritage**. As a trusted name in aftermarket automotive parts, National has built a reputation for producing components that meet or exceed OEM specifications, ensuring that your Porsche retains its original performance and character. Whether you re performing a routine maintenance overhaul, addressing a persistent oil leak, or restoring a vintage 911 to its former glory, the **National 226520** provides the confidence of a professional-grade solution.

Installation of the **National 226520** is straightforward, though it is recommended to follow proper torque specifications and use a high-quality gasket maker to ensure a secure seal. Proper surface preparation including cleaning and deburring the mating surfaces is essential to prevent premature failure. Once installed, this seal helps maintain the integrity of your engine s lubrication system, reducing friction, overheating, and wear on critical components like the rear main seal and transmission bearings.

For Porsche owners who demand nothing less than perfection, the **National 226520 Rear Engine Seal** is an indispensable part of any maintenance or restoration project. Its combination of **durability, precision engineering, and compatibility** makes it the ideal choice for preserving the performance and authenticity of your classic Porsche ensuring that your engine remains as reliable and powerful as the day it left the factory.

### **Pros and Cons of Buying a National 226520 Rear Engine Seal (Porsche 911 65-77, 2.0L 2.7L H6)**

1. **Compatibility** This seal is designed specifically for Porsche 911 models from 1965 to 1977 with 2.0L, 2.2L, 2.3L, 2.4L, and 2.7L H6 engines, ensuring a precise fit without modification.

2. **Reliability** National is a well-known manufacturer of high-quality automotive seals, known for durability and resistance to oil and heat, which helps prevent leaks over time.

3. **Ease of Installation** The seal is designed to fit standard tools and procedures, making it accessible for both professional mechanics and experienced DIYers.

4. **Prevents Major Damage** A failing rear engine seal can lead to oil leaks, which can damage the engine, transmission, and exhaust system. Replacing it early prevents costly repairs.

5. **Long-Term Cost Savings** While the upfront cost is moderate, replacing the seal proactively avoids more expensive engine or transmission damage later.

6. **Warranty Coverage** Some aftermarket suppliers offer warranties on their seals, providing peace of mind against premature failure.

7. **Improved Performance** A properly sealed engine bay reduces oil leaks, which can improve engine efficiency and longevity.

1. **Cost** The seal itself is relatively inexpensive, but labor costs for replacement (especially in a Porsche) can be high, particularly if done by a specialist.

2. **Complexity of Installation** Removing and reinstalling the rear engine seal requires disassembling parts of the engine bay, which can be time-consuming and technically challenging for inexperienced DIYers.

3. **Potential for Additional Wear** If the seal failure was due to underlying issues (e.g., worn gaskets, improper maintenance, or excessive heat), replacing just the seal may not fully resolve the problem.

4. **Risk of Oil Leaks During Installation** Improper installation can lead to leaks, requiring rework and potentially more downtime.

5. **Availability of Parts** While the seal itself is widely available, some older Porsche models may require additional specialty tools or parts (e.g., clamps, gaskets) that could add to the cost.

6. **Time Off the Road** A full replacement job can take several hours, depending on the mechanic s experience and the condition of surrounding components.

7. **Potential for Counterfeit Products** If purchasing from an untrusted source, there is a risk of receiving a low-quality or fake seal that fails prematurely.

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### **Conclusion**

The **National 226520 rear engine seal** is a solid, reliable choice for Porsche 911 owners from 1965 1977 with H6 engines. Its primary advantage is preventing catastrophic engine or transmission damage from oil leaks, which can be far more costly than the seal replacement itself. However, the installation process is labor-intensive and may require professional help, especially for those unfamiliar with Porsche mechanics.

If you re experiencing **visible oil leaks, burning smells, or oil spots under your car**, replacing the seal is a **necessary preventive measure**. If the seal is being replaced **proactively as part of routine maintenance**, it s still a wise investment to avoid future issues.

For **best results**, ensure the installation is done correctly either by a trusted Porsche specialist or a mechanic experienced with classic cars. Additionally, inspect surrounding components (gaskets, clamps, and seals) during the job to catch any other potential failure points.

- **If you have symptoms of a failing rear engine seal (leaks, smoke, oil loss), replace it as soon as possible.**

- **If replacing as preventive maintenance, do it every 50,000 100,000 miles or as recommended by your mechanic.**

- **Purchase from a reputable supplier (e.g., National s official distributors, RockAuto, or specialty Porsche parts stores) to avoid counterfeit products.**

- **Consider professional installation if you lack experience with Porsche engine bay work.**

Ultimately, this seal is a **cost-effective solution** to avoid far more expensive engine or transmission repairs down the line. Proper maintenance now will extend the life of your Porsche and keep it running smoothly.

Details:

Shipping: Free Shipping is for contingent USA only. Country of Origin: origin is stated on product packaging. National part number 226520. These items, although NEW, may contain shelf wear or imperfections due to the age of product.

Please refer to the products photograph for actual country of origin. Free Shipping is for continental USA only.

part #: 226520 prices

• $13.85-$17.99

specifications cranshafengin:

• for makes: Porsche
• brand: National
• mpn: 226520
• part type: Seal Engine
• placement on vehicle: Rear

payments cranshafengin:

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• wallet: Paypal
• other

seller cranshafengin:

• # reviews: 285692
• rating: 99.8%
• city: Houston, Texas

offer cranshafengin:

• options: Ship-to-home
• availability: In Stock
• sold: 0
• quantity: 1
• started: May 11, 2026

shipping cranshafengin:

• type: Fixed
• service: Standard
• transit: 3-8 Days
• class: Standard
• cost: $0.00

general cranshafengin:

• Car Truck Parts Accessories > Engines Engine Parts > Crankshafts
• condition: New other see details

returns cranshafengin:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

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