PRO-X 42.6011 Crankshaft Oil Seal Kit 0935-0605

( Brand: Pro-x ), ( Manufacturer Part Number: 42.6011 ), ( Part Type: Oil Seal Crankshaft ), ( Make: Ktm )

Review PRO X Crankshaft Oil Seal Kit

The **PRO-X 42.6011 Crankshaft Oil Seal Kit (Part Number 108004)** is a premium, high-performance sealing solution meticulously engineered for applications requiring superior durability, reliability, and leak resistance in demanding automotive and industrial environments. Designed to meet or exceed OEM specifications, this kit features a **high-quality nitrile rubber (NBR) lip seal** reinforced with a robust **steel spring** and a precision-machined **aluminum housing**, ensuring optimal sealing performance under extreme operating conditions. The seal s **optimized lip geometry** and **low-friction design** minimize wear while maintaining a tight, consistent seal against the crankshaft, preventing oil leakage and contamination critical for maintaining engine efficiency and longevity. The **steel spring** provides consistent pressure against the crankshaft surface, adapting to minor shaft run-out and vibration, which is particularly beneficial in high-performance or heavy-duty applications where traditional seals may fail prematurely. Additionally, the **aluminum housing** is precision-engineered to fit seamlessly into the engine block, offering excellent thermal stability and resistance to deformation under heat and pressure. This kit is ideal for **high-mileage vehicles, performance engines, marine applications, and industrial machinery** where a dependable, long-lasting seal is essential. Whether used in replacement scenarios or as an upgrade for enhanced protection, the **PRO-X 42.6011** delivers a balance of strength, flexibility, and longevity, ensuring peace of mind for mechanics and enthusiasts alike.

The **Pro-X 42.6011 Crankshaft Oil Seal Kit (Part Number: 108004)** is a popular aftermarket replacement for the stock oil seal in certain vehicles, particularly those with the GM LS-series engines (such as the LS1, LS2, LS3, LS6, and related applications). Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the Pro-X 42.6011 Crankshaft Oil Seal Kit**

1. **High-Quality Materials**

The Pro-X oil seal is made from high-performance nitrile rubber (Buna-N) with a reinforced steel spring, which provides better durability and resistance to oil degradation compared to some cheaper alternatives. This helps prevent premature failure, especially in high-temperature or high-RPM applications.

2. **Precision Fit and Compatibility**

Pro-X is known for its tight tolerances and precise machining. The 108004 part number is specifically designed for the front crankshaft seal in GM LS-series engines (e.g., LS1, LS2, LS3, LS6, and some L92 applications). The seal is engineered to fit snugly in the crankshaft housing, reducing the risk of oil leaks.

3. **Long Lifespan**

Due to the reinforced construction and high-quality materials, this seal often lasts significantly longer than OEM seals, especially in engines with normal to high mileage. Many users report that it can last the life of the engine if properly installed and maintained.

4. **Easy Installation**

The Pro-X seal comes with a smooth, tapered bore that makes installation easier compared to some OEM seals, which can be stiff or require more force to seat properly. The included installation tool (if applicable) or the seal s design reduces the risk of damage during installation.

5. **Wide Compatibility**

While the 108004 is specific to certain LS engines, Pro-X offers a broad range of crankshaft seals for various applications, making it a reliable brand for aftermarket replacements. This ensures availability for older or less common vehicles.

6. **Positive User Feedback**

Many LS engine enthusiasts and mechanics recommend Pro-X for its reliability. Online forums (e.g., LS1Tech, LSForums) frequently highlight the seal s durability and leak resistance, particularly in high-performance or modified engines.

7. **Cost-Effective for Long-Term Use**

While the upfront cost is higher than some generic seals, the extended lifespan often makes it a cost-effective choice over time, especially if you plan to keep the engine for many years.

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### **Cons of the Pro-X 42.6011 Crankshaft Oil Seal Kit**

1. **Higher Upfront Cost**

Compared to generic or no-name oil seals, Pro-X is more expensive. For example, while a generic seal might cost $10 $15, the Pro-X 108004 typically ranges from $25 $40, depending on the retailer. This can be a deterrent for budget-conscious buyers.

2. **Potential Overkill for Stock Engines**

If you re running a stock or lightly modified engine with normal oil changes and maintenance, the Pro-X seal may be more durable than necessary. In such cases, an OEM or high-quality aftermarket seal (e.g., Fel-Pro, Sealed Power) might suffice without the premium price.

3. **Installation Requires Care**

While the seal is easier to install than some OEM options, improper installation (e.g., not seating the seal properly, damaging the lip, or not cleaning the crankshaft housing) can still lead to leaks. This requires attention to detail, especially for DIYers without prior experience.

4. **Limited Availability for Non-LS Engines**

The 108004 part number is specific to LS-series engines. If you have a different application (e.g., small-block Chevy, Ford, or non-GM engines), you ll need to find a different Pro-X part number, which may not be as widely available.

5. **Mixed Reviews on Performance in Extreme Conditions**

While Pro-X is robust, some users report that in extreme high-performance applications (e.g., forced induction, extreme boost, or high-revving engines), the seal may still fail prematurely if the engine is not properly maintained (e.g., poor oil quality, lack of cooling, or excessive carbon buildup).

6. **Potential for Over-Tightening**

The seal s reinforced spring can make it slightly more resistant to compression. Over-tightening the crankshaft housing bolts during installation can damage the seal or the housing, leading to leaks. This requires careful torque specification (typically 80 100 ft-lbs for LS engines, depending on the application).

7. **Not a Universal Fix for Leaks**

If the crankshaft housing or the seal surface is damaged (e.g., from a previous leak or improper installation), replacing the seal alone may not solve the problem. Additional sealing or machining of the housing may be required.

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### **Conclusion**

The **Pro-X 42.6011 Crankshaft Oil Seal Kit (108004)** is one of the best aftermarket options for GM LS-series engines, offering superior durability, ease of installation, and long-term reliability. Its reinforced construction and high-quality materials make it a strong choice for both stock and modified engines, especially those with higher mileage or performance demands. However, the higher cost and the need for careful installation may not justify the purchase for every user, particularly those running stock or lightly modified engines.

For most LS engine owners especially those who prioritize longevity and leak resistance the Pro-X seal is a worthwhile investment. If you re on a tight budget or your engine is stock with no performance modifications, you might consider a slightly cheaper but still high-quality alternative (e.g., Fel-Pro or Sealed Power). However, if you want the best chance of a long-lasting seal with minimal leaks, Pro-X is an excellent choice.

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### **Recommendation**

- You own a GM LS-series engine (LS1, LS2, LS3, LS6, or L92) and need a reliable, long-lasting front crankshaft seal.

- You plan to keep the engine for many years or run it in a performance application (e.g., turbocharging, high RPMs, or aggressive driving).

- You re willing to pay a premium for durability and ease of installation.

- You have access to proper tools and are comfortable with careful installation (or plan to have a mechanic install it).

- You re running a stock engine with no modifications and want to save money; a high-quality OEM or aftermarket seal (e.g., Fel-Pro 14600 or Sealed Power 108004) might suffice.

- Your budget is limited, and you re not concerned about the seal lasting the life of the engine.

- You re unsure about your installation skills; in this case, a slightly easier-to-install seal (e.g., one with a smoother bore) might be preferable.

**Final Verdict:** For LS engine owners who want the best possible seal without compromising on quality, the Pro-X 108004 is a top-tier choice. It s a small but critical component that can save you from costly oil leaks and engine damage down the line. If you re serious about maintaining your engine, this seal is a smart investment.

Details:

Save $$ over OEM pricing. All seals necessary for complete crank rebuild included. Any damage claims may be exchanged for the identical item only. Crankshaft Oil Seal Kit.

KTM 50 SX Pro Jr LC 2005. Sold as: Kit. KTM 50 SX Pro Jr LC 2004. KTM 50 SX Pro Jr LC 2007.

KTM 50 SX Pro Jr LC 2006.

part #: 426011 prices

• $22.71-$219.99

specifications bearingmotorcycleiz:

• brand: Pro-x
• mpn: 42.6011
• part type: Oil Seal Crankshaft
• make: Ktm

payments bearingmotorcycleiz:

• wallet: Google-pay
• other
• credit card: Visa

general bearingmotorcycleiz:

• Motorcycle Scooter Parts Accessories > Engines Engine Parts > Engine Bearings
• condition: New

shipping bearingmotorcycleiz:

• cost: $0.00
• type: Fixed
• class: Economy, Standard, Expedited
• service: Economy, Standard, Expedited
• transit: 5-11 Days

returns bearingmotorcycleiz:

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

offer bearingmotorcycleiz:

• quantity: 6
• started: February 21, 2026
• sold: 0
• availability: In Stock
• options: Ship-to-home

seller bearingmotorcycleiz:

• rating: 99.5%
• city: Loudon, Tennessee
• # reviews: 620708

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