MOPAR 1266009 Idler Shaft Lock Plate Nos

( Manufacturer Part Number: 1266009 ), ( Part Type: Idler Shaft Lock Plate )

Review MOPAR Idler Shaft Lock Plate Nos

The **Mopar 1266009 Idler Shaft Lock Plate** is a precision-engineered component designed to ensure optimal performance and longevity in Mopar-equipped vehicles, particularly those featuring the iconic 318, 360, and 400 cubic inch inline-six engines. This high-quality lock plate serves as a critical retention mechanism, securely fastening the idler shaft assembly in place within the valve cover housing, preventing unwanted movement or misalignment that could lead to premature wear, valve train issues, or even catastrophic engine failure. Crafted from durable, heat-treated steel, the lock plate is engineered to withstand the high temperatures and mechanical stresses encountered in high-performance and heavy-duty applications, ensuring reliable operation under demanding conditions. Its unique design incorporates a split-pin or cotter pin hole, allowing for easy installation and removal while maintaining a tight, interference-fit seal that resists loosening over time. This component is essential for maintaining proper valve lash and camshaft timing, as any misalignment or displacement of the idler shaft could result in erratic engine behavior, excessive noise, or even valve-to-piston contact in severe cases. Whether used in classic muscle cars, high-mileage workhorses, or restored vintage vehicles, the **Mopar 1266009 Idler Shaft Lock Plate** provides the necessary precision and durability to keep the valve train operating smoothly, ensuring peak engine performance and reliability. Always pair this part with genuine Mopar seals, gaskets, and fasteners to guarantee a complete and long-lasting repair.

The **Mopar 1266009 Idler Shaft Lock Plate** is a critical component for the proper functioning of the idler arm in certain Chrysler vehicles, particularly those with the **426 Hemi engine** or related applications. Below are the key pros and cons of purchasing this part, followed by a conclusion and recommendation.

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### **Pros of buying a Mopar 1266009 Idler Shaft Lock Plate**

1. **OEM Quality and Fit**

- Mopar is Chrysler s official aftermarket brand, meaning this part is designed to match the original equipment specifications exactly. It should fit seamlessly without modifications, reducing the risk of misalignment or improper function.

2. **Reliability and Durability**

- As an OEM or high-quality aftermarket part, it is typically manufactured to withstand the stress of high-performance applications, including forced induction (turbo/supercharged) setups. This can extend the lifespan of the idler arm assembly.

3. **Compatibility with Performance Modifications**

- Many high-performance builds, especially those involving valve springs, camshafts, or forced induction, require precise valve train components. The 1266009 lock plate is often necessary to ensure proper valve lash and timing, preventing issues like valve float or excessive wear.

4. **Ease of Installation**

- Since it is a direct replacement, installation is straightforward and doesn t require specialized tools beyond basic socket and wrench sets. This makes it accessible for DIYers and mechanics alike.

5. **Support for Restored or Rebuilt Engines**

- If you re restoring a classic 426 Hemi or rebuilding an engine, using OEM or Mopar parts ensures compatibility with other restored components, maintaining the engine s integrity and performance.

6. **Warranty and Support**

- Mopar parts often come with warranties, providing some recourse if the part fails prematurely due to manufacturing defects. Chrysler dealerships and authorized Mopar distributors can offer technical support if needed.

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### **Cons of buying a Mopar 1266009 Idler Shaft Lock Plate**

1. **Cost**

- As an OEM or high-quality aftermarket part, the 1266009 lock plate can be more expensive than generic or non-branded alternatives. For budget-conscious buyers, this may be a significant drawback, especially if the part is only needed for a specific application.

2. **Limited Availability**

- Mopar parts, while widely available, may not be stocked at every auto parts store. You might need to order it online or visit a specialty performance shop, which could add to the total cost or wait time.

3. **Potential for Overkill**

- If you re not running a high-performance or heavily modified engine, this part might be unnecessary. For stock or mildly modified engines, a less expensive generic lock plate could suffice without sacrificing performance or reliability.

4. **Mixed Reviews on Aftermarket Alternatives**

- While Mopar is reputable, some buyers report that aftermarket alternatives (e.g., from brands like **Eagle, Crane, or Summit Racing**) offer comparable quality at a lower price. Researching alternatives may reveal equally good options.

5. **Risk of Counterfeit Parts**

- Purchasing from untrusted sellers (especially online marketplaces) could result in counterfeit or low-quality parts. Always buy from reputable dealers or authorized Mopar distributors to avoid this risk.

6. **Installation Complexity for Beginners**

- While the installation itself is simple, removing the old lock plate may require careful disassembly of the valve train. Inexperienced DIYers might struggle with tasks like removing the rocker arms or adjusting valve lash, potentially leading to mistakes or damage.

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### **Conclusion**

The **Mopar 1266009 Idler Shaft Lock Plate** is a high-quality, reliable choice for those rebuilding or modifying a **426 Hemi or related high-performance engine**. Its OEM specifications, durability, and compatibility with performance applications make it a strong option for serious enthusiasts. However, the higher cost and potential overkill for stock engines may deter some buyers. If budget is a concern, researching aftermarket alternatives could yield equally good results without sacrificing performance.

For most **high-performance or restored 426 Hemi applications**, the Mopar part is the safest and most reliable option. For stock or lightly modified engines, a generic replacement might be sufficient.

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### **Recommendation**

- You re rebuilding or modifying a **426 Hemi or similar high-performance engine**.

- You prioritize OEM quality and long-term reliability.

- You re confident in your ability to install it correctly (or are working with a trusted mechanic).

- You re on a tight budget and the engine isn t heavily modified.

- You find a reputable aftermarket brand (e.g., **Crane, Eagle, or Summit Racing**) offering a comparable part at a lower price.

- You re unsure about the necessity of the part for your specific application consult a mechanic or engine specialist first.

Always purchase from **authorized Mopar dealers or trusted online retailers** to avoid counterfeit parts. If in doubt, verify compatibility with your engine s build specifications before purchasing.

Details:

All parts are in stock and ready to ship. Mopar 1266009 Idler Shaft Lock Plate NOS. Items are shipped using USPS, UPS, and FedEx.

Shows signs of shelf wear. Idler Shaft Lock Plate is new and in good condition, original packaging. If the original package is included it may show signs of wear.

part #: 1266009 price

• $31.49

specifications pitmanidlear:

• for makes: Mopar
• mpn: 1266009
• part type: Idler Shaft Lock Plate

seller pitmanidlear:

• rating: 99.9%
• city: Ashaway, Rhode Island
• # reviews: 128931

payments pitmanidlear:

• other
• credit card: Discover
• wallet: Paypal

shipping pitmanidlear:

• cost: $0.00
• carrier: USPS, UPS
• transit: 4-9 Days
• type: Calculated
• class: Standard, Expedited, One-day
• service: USPS Ground Advantage, USPS Priority Mail Flat Rate Envelope, UPS Next Day Air, UPS 2nd Day Air

general pitmanidlear:

• condition: New
• Car Truck Parts Accessories > Steering Suspension > Pitman Idler Arms

offer pitmanidlear:

• sold: 0
• options: Ship-to-home
• quantity: 3
• started: March 4, 2026
• best offers: True
• availability: In Stock

returns pitmanidlear:

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

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