1. Lock Hardware Deals
  2. sku: 31351805602093663
  3. MERCEDES 450SL

MERCEDES Lock Actuator 643.MB1U73 Benz

fits model: 450sl. make: Mercedes. year: 1973.

643.mb1u73 Mercedes-benz 450sl 1973 Lock Actuator 304650

( Part Type: Actuator Lock ), ( Conditions Options: Lh ), ( Genuine Oem: Yes ), ( Ipn: 643.mb1u73 ), ( Make: Mercedes-benz ), ( Manufacturer Warranty: 60 Day )

Review MERCEDES benz Lock Actuator fits 450SL 1973

The **Mercedes-Benz 643.MB1U73 lock actuator** from the iconic **1973 450SL** is a meticulously engineered component that embodies the precision and reliability synonymous with the legendary "Pagoda" roadster. This critical part plays a pivotal role in the vehicle s electrical locking mechanism, ensuring seamless operation of the doors, trunk, and hood while maintaining the car s signature blend of performance and luxury. Crafted to exacting standards, the actuator is designed to withstand the demands of daily driving, offering smooth engagement and disengagement of the locking pins with minimal wear. Its robust construction, featuring high-quality materials and a durable housing, guarantees longevity even under the rigorous use typical of a classic sports car. The 643.MB1U73 is a direct-fit replacement, meticulously designed to replicate the original functionality of the factory unit, including the precise electrical connections and mechanical linkages that interface with the car s wiring harness and door mechanisms. Whether restoring a showroom-worthy 450SL or maintaining a daily driver, this actuator is an essential component for preserving the integrity of the vehicle s electrical system, ensuring that every lock and unlock cycle operates with the same effortless authority as the day it left the factory. For enthusiasts and restorers, sourcing an authentic 643.MB1U73 actuator is a testament to the enduring craftsmanship of Mercedes-Benz, bridging the gap between vintage engineering and modern reliability.

### **Pros and Cons of Buying a 1973 Mercedes-Benz 643.MB1U73 450SL (Lock Actuator Issue)**

#### **Pros**

1. **Classic Design and Prestige** The 450SL is an iconic 1970s Mercedes-Benz sports car with a timeless, elegant design. It carries significant prestige among collectors and enthusiasts, making it a desirable piece of automotive history.

2. **Strong Engine and Performance** The 4.5L M116 inline-six engine (250 282 hp, depending on modifications) delivers solid power for its era. With proper maintenance, it can still provide enjoyable driving dynamics, especially in a roadster configuration.

3. **Vintage Driving Experience** The manual transmission (if available) and classic suspension tuning offer a more engaging, less isolated driving experience compared to modern cars. The open-top design enhances the sense of freedom.

4. **Potential for Restoration and Customization** Many owners enjoy restoring or modifying these cars to original or modernized specifications. The aftermarket support for parts (especially in Europe and among enthusiasts) can make maintenance and upgrades feasible.

5. **Investment Potential** Well-preserved examples, especially those with originality or rare features (e.g., convertible top, specific paint schemes), can appreciate in value over time, particularly if demand for classic Mercedes continues to grow.

6. **Community and Support** There is a strong community of 450SL owners and restorers who share knowledge, parts, and restoration tips. Clubs like the **Mercedes-Benz 450SL Club** provide networking and technical assistance.

7. **Reliability (If Well-Maintained)** With proper care, the engine and chassis can last for decades. Many original 450SLs still run today, though mechanical wear is inevitable over 50 years.

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#### **Cons**

1. **High Maintenance Costs** Classic Mercedes-Benz cars require frequent, specialized maintenance. Parts (especially original or high-quality reproductions) can be expensive, and labor costs for restoration or repairs are often prohibitive.

2. **Lock Actuator Issue (Specific to This Example)** The mention of a lock actuator problem suggests potential electrical or mechanical failures in the door locks or ignition. These issues may require professional diagnosis and repair, adding to costs. Electrical systems in older Mercedes can be finicky and may need rewiring or component replacements.

3. **Rust and Structural Corrosion** Many 1970s Mercedes, especially those exposed to harsh climates, suffer from rust in critical areas like the chassis, suspension, and body panels. A thorough inspection is essential to avoid costly structural repairs.

4. **Originality vs. Restoration Trade-Off** Restoring a 450SL to original condition can be expensive, while modernizing it (e.g., suspension, brakes, interior) may reduce its collectible value. Finding the right balance is key.

5. **Parts Availability and Lead Times** While some parts are still available, others may require sourcing from specialty suppliers or dismantled donor cars. Lead times can be long, disrupting restoration projects.

6. **Driving Challenges** Modern road conditions, traffic, and safety standards may make the 450SL less practical for daily use. Visibility can be limited, and the car s weight (especially with a heavy body) affects handling compared to modern sports cars.

7. **Insurance Costs** Classic car insurance can be expensive, particularly for high-value or restored examples. The lock actuator issue may also affect insurability or premiums.

8. **Time-Consuming Projects** Restoring or maintaining a 450SL is a labor-intensive process. Owners must be prepared for long hours of work, whether DIY or outsourced.

9. **Market Saturation** While demand exists, the supply of well-preserved 450SLs is relatively high. Finding a truly exceptional example without major issues can be competitive and costly.

10. **Depreciation Risk** Unlike some highly sought-after classics, the 450SL is not as consistently appreciating as rarer models (e.g., 300SL Gullwing). Its value depends heavily on condition, provenance, and market trends.

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### **Conclusion**

Buying a 1973 Mercedes-Benz 450SL with a lock actuator issue is a decision that hinges on your priorities: **passion for classic cars, restoration enjoyment, or investment potential**. If you are an experienced restorer with deep pockets and patience, this car can be a rewarding project. However, if you seek a practical, low-maintenance vehicle or lack the expertise to handle its quirks, the costs and challenges may outweigh the benefits.

The lock actuator issue is a red flag that suggests either immediate repair costs or a deeper electrical/mechanical problem that could escalate. A thorough pre-purchase inspection by a trusted Mercedes specialist is **mandatory** to assess the extent of the issue and other hidden problems (e.g., rust, engine wear, transmission condition).

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### **Recommendation**

1. **If You Are Serious About the Purchase:**

- **Get a Professional Inspection:** Hire a Mercedes specialist to evaluate the lock actuator, electrical system, engine, transmission, and body condition. Request a detailed written report.

- **Budget for Repairs:** Factor in the cost of fixing the lock actuator and any other issues uncovered. Be prepared for unexpected expenses (e.g., $2,000 $10,000 for major restorations).

- **Verify Originality:** Decide whether you want an original car or a restored one. Originality adds value but may require more work.

- **Test Drive Thoroughly:** Check for smooth operation of all mechanical and electrical systems, including the locks, ignition, and suspension.

2. **If You Are Unsure or New to Classics:**

- **Consider a Less Expensive Classic:** Models like the **280SL, 300SL, or even later 1980s Mercedes** may offer similar driving experiences with lower maintenance costs.

- **Start with a Restored Example:** A car that has already undergone a full restoration (with documentation) reduces risk but may cost more upfront.

- **Join the Community:** Engage with 450SL forums or clubs to learn from experienced owners before committing.

3. **Alternative Approach:**

- **Buy as a Project Car:** If you have mechanical skills and time, this could be a fulfilling long-term project. However, ensure you can afford to live without the car during restoration.

- **Negotiate Price:** If the lock actuator issue is confirmed, use it as leverage to lower the purchase price to account for repair costs.

**Final Verdict:** The 1973 450SL is a fantastic car for the right owner someone who loves tinkering, appreciates vintage engineering, and can handle the financial and time commitments. However, it is not a car for casual buyers or those seeking a hassle-free ownership experience. **Proceed only after thorough due diligence and with a realistic budget.**

Details:

Engines are guaranteed against knocking and excessive smoking. Fill trans with manufacture specified fluid. Prior to installation of your used engine we require these steps be taken for warranty valid. Flush and inspect cooling lines.

Pre-Installation requirements: Replace all seals. Install new filter kit. Engine Warranty Installation Procedures. Replace thermostat gasket.

Transmission Warranty Installation Procedures Prior to installation of your used transmission we require these steps be taken for warranty valid. Replace valve cover gaskets. Adjust throttle position sensor cable. Install new belts and hoses.

Install new spark plugs wires. Align and engage torque converter into front pump. If needed replace timing gears, chains or belts gaskets. Replace oil pan gasket and rear main seal.

Clear all transmission computer codes prior to starting or operating vehicle. Replace oil, air and fuel filters. Flush cooling system and re-fill. Our entire inventory comes with a minimum 60-day limited warranty.

Pre-Installation Requirements: Drain and replace engine oils to manufacture suggested levels.

specifications carlockiio:

  • for models: 450sl
  • for makes: Mercedes
  • for years: 1973
  • part type: Actuator Lock
  • conditions options: Lh
  • genuine oem: Yes
  • ipn: 643.mb1u73
  • make: Mercedes-benz
  • manufacturer warranty: 60 Day

seller carlockiio:

  • # reviews: 2992
  • rating: 99.5%
  • city: Medford, New York

general carlockiio:

  • condition: Used
  • Car Truck Parts Accessories > Exterior Parts Accessories > Exterior Locks Lock Hardware

shipping carlockiio:

  • transit: 4-11 Days
  • cost: $0.00
  • carrier: USPS
  • service: USPS Priority Mail
  • class: Expedited
  • type: Fixed

returns carlockiio:

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

offer carlockiio:

  • quantity: 1
  • availability: In Stock
  • best offers: True
  • started: May 5, 2026
  • sold: 0
  • options: Ship-to-home

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for models: 450sl, for makes: mercedes, for years: 1973, part type: actuator lock, conditions options: lh, genuine oem: yes, manufacturer warranty: 60 day,
manufacturer: mercedes-benz, category: auto parts > car truck parts accessories > exterior parts accessories > exterior locks lock hardware, sku: 31351805602093663,
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