Purchasing a classic car like a 1978 Mercedes 450sl is an exciting venture. Known for its timeless design and robust engineering, the 450SL from the R107 generation remains a sought-after vehicle. However, like any car of this vintage, a thorough inspection is crucial before making a purchase. This checklist, tailored for the discerning buyer, will guide you through the key areas to examine on a 1978 Mercedes 450SL, ensuring you invest wisely in your dream classic.
Critical Areas to Inspect on a 1978 Mercedes 450SL
When evaluating a 1978 Mercedes 450SL, several points require careful scrutiny. We’ll delve into the most important aspects, focusing on common issues and areas prone to wear and tear in these iconic vehicles.
Rust: The Undeniable Enemy
Rust is, unfortunately, a prevalent concern in older Mercedes models, and the 450SL is no exception. A meticulous rust inspection is paramount.
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Body Panels: Start with a visual inspection of all body panels. Pay close attention to areas like wheel arches, rocker panels, door bottoms, and around the headlights and taillights. Look for bubbling paint, which is a telltale sign of rust underneath.
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Subframe and Undercarriage: The subframe recall is a critical point. Verify if this recall has been performed. Check the subframe itself for rust, especially at mounting points. Thoroughly examine the entire undercarriage for rust, paying attention to floor pans, chassis rails, and suspension components. Use a flashlight to illuminate hard-to-see areas. Rust in structural areas can be costly and complex to repair.
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Battery Tray Area: Battery acid can cause significant rust damage. Inspect the area around the battery tray meticulously for corrosion and rust.
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Spare Tire Well: Lift the spare tire and inspect the well beneath it for trapped water and rust accumulation.
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Behind Headlights: These areas are known to trap water. Check behind the headlights for rust, as these are often overlooked spots.
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Floor Pans (Interior): Don’t just check exterior rust. Lift carpets, padding, and damping material inside the car, particularly in the footwells and under the seats. Rust here can indicate serious water ingress issues.
Mechanical Components: Ensuring Longevity and Performance
Beyond rust, the mechanical condition of a 1978 Mercedes 450SL is equally vital.
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Climate Control System: Determine the type of climate control system (manual or automatic) and thoroughly test its functionality. Ensure the air conditioning blows cold and the heater blows hot. Check all fan speeds and vent controls. Malfunctioning climate control can be expensive to repair.
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Control Arm Bushings, Subframe Mounts, and Engine Mounts: These rubber components degrade over time. Inspect the condition of control arm bushings for cracks or excessive wear. Check subframe mounts and engine mounts for deterioration, which can lead to vibrations and handling issues.
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Steering System Play: Check for excessive play in the steering wheel. More than 1 1/2 inches of play can indicate worn steering coupler bushings. Replacing these bushings is a labor-intensive job.
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Flex Joints (Guibo Discs): Examine the age and condition of the flex joints (Guibo discs) in the driveshaft. Cracks or deterioration mean they need replacement to prevent driveline vibrations and potential failure.
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Vacuum Control Lines: Carefully inspect the condition, presence, and proper routing of vacuum control lines throughout the engine bay. These lines are crucial for various systems, including the transmission, emissions, and climate control. Cracked or disconnected lines can cause numerous problems.
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Timing Chain and Guides: Inquire about the timing chain and guides. Ask for maintenance records to see if they have been replaced. If not, this is a significant maintenance item to consider, as failure can lead to severe engine damage.
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Blower Motor: Test the blower motor for proper function and listen for unusual noises like squealing or grinding, which can indicate wear or impending failure.
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Cruise Control System: Engage the cruise control system and verify that it engages, holds speed, and disengages correctly. A functioning cruise control adds to the driving enjoyment of a classic car.
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Shifter Play (Automatic Transmission): For automatic models, check the shifter for excessive play. Excessive play often indicates worn shift linkage bushings, which should be addressed for smooth gear changes.
Body and Top: Aesthetics and Functionality
The 450SL’s iconic convertible nature makes the condition of the soft and hard tops crucial.
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Soft Top Condition: Inspect the soft top material for tears, wear, and discoloration. Pay particular attention to the plastic windows, checking for cracks, clouding, and yellowing. Test the operation of the soft top mechanism to ensure smooth and proper deployment and retraction.
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Window Seals (Soft and Hard Tops): Check the seals around the windows on both the soft and hard tops for dryness, cracking, and proper sealing against the body. Leaks can lead to interior water damage and rust.
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Top Release Handles and Mechanisms: Operate the release handles and mechanisms for both the hard and soft tops to ensure they function smoothly and securely latch and unlatch.
Electrical and Miscellaneous Checks
Don’t overlook the electrical system and general condition.
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Wiring and Lights: As with any older vehicle, inspect the condition of the wiring and lights. Check all lights (headlights, taillights, turn signals, brake lights, interior lights) for proper function. Look for cracked or brittle wiring insulation, which is common in older cars.
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Plastic Covers and Shields: Inspect for cracked or missing plastic covers and shields in the engine bay and undercarriage. These components protect vital parts and contribute to the car’s overall presentation.
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Maintenance Records: Request and carefully review all available maintenance records. These records provide valuable insight into the car’s history, previous repairs, and overall care. Pay attention to the dates and details of services performed.
Conclusion: Due Diligence for Classic Car Ownership
Purchasing a 1978 Mercedes 450SL can be a rewarding experience. However, thorough due diligence is essential. This checklist provides a comprehensive guide to inspecting key areas of the vehicle, with a strong emphasis on rust, mechanical condition, and the functionality of essential systems. By meticulously following these steps, you’ll be well-equipped to make an informed decision and enjoy your classic 450SL for years to come. Remember, when in doubt, a pre-purchase inspection by a qualified Mercedes-Benz mechanic is always a worthwhile investment.
