Restoring the 1969 Clark 35 AWS: Challenges for Classic Equipment Enthusiasts

[MikePhua]

The 1969 Clark 35 AWS is a vintage piece of heavy machinery that embodies the era's design and engineering standards. While it may not boast the high-tech features of modern equipment, it remains a favorite among collectors and professionals who appreciate its durability and history. However, maintaining or restoring such a machine presents unique challenges, as parts are scarce, and finding skilled technicians familiar with older models can be tricky. In this article, we will explore common issues with the Clark 35 AWS, the restoration process, and lessons learned from operators and restorers.
The Clark 35 AWS: A Classic Crawler Loader
Introduced in the late 1960s, the Clark 35 AWS was part of the company’s range of crawler loaders designed for versatility and durability. It was equipped with a diesel engine and a robust transmission system that made it a reliable choice for tasks such as digging, lifting, and moving materials. Despite being a solid performer, the 35 AWS, like many older machines, requires special attention to keep it in working condition, particularly given the age of its components.
Common Issues with the Clark 35 AWS

1. Engine Performance Problems
   

Over time, the engine of the Clark 35 AWS can begin to show signs of wear, especially with older models that have accumulated many hours of operation. Common issues include poor starting performance, reduced power, and irregular idling. These problems are typically due to:

• Fuel system clogging: Old fuel lines, dirty injectors, or clogged filters can restrict fuel flow, leading to engine performance issues.
  
• Compression loss: Worn-out piston rings or valve seals can lead to reduced engine compression, causing power loss and hard starting.
  
• Cooling system issues: A malfunctioning cooling system can lead to overheating, which may result in permanent engine damage if not addressed.
  

Troubleshooting Engine Problems
To restore engine performance, begin by checking the fuel system for blockages and replacing any old, cracked fuel lines. Clean or replace the fuel injectors and fuel filters as needed. For compression loss, a compression test will help identify if the pistons or valves need to be replaced. Lastly, ensure the radiator and coolant system are functioning properly to prevent overheating.

1. Hydraulic System Failures
   

The hydraulic system in the Clark 35 AWS plays a crucial role in lifting and moving materials. As with many older machines, hydraulic system failures can arise from several issues:

• Leaking hoses: Over time, hydraulic hoses can wear out, leading to leaks that reduce system pressure.
  
• Low fluid levels: Inadequate hydraulic fluid levels can lead to sluggish or unresponsive hydraulic cylinders.
  
• Worn-out seals and valves: These components can degrade over time, causing leaks and a drop in hydraulic performance.
  

Troubleshooting Hydraulic Issues
Start by inspecting all hydraulic hoses for leaks or wear and replacing damaged hoses. Next, check the hydraulic fluid levels and top them off if needed. If the hydraulic performance is still lacking, inspect the seals, valves, and pumps for wear. Replacing any worn-out parts can restore the system to optimal working condition.

1. Transmission and Drive Train Problems
   

The Clark 35 AWS’s transmission and drivetrain are critical for its operation, and problems in these areas can cause the machine to lose traction or fail to move efficiently.

• Clutch wear: Over time, the clutch system can wear down, resulting in difficulty shifting gears or slippage.
  
• Gearbox issues: If the transmission fluid is low or contaminated, it can cause rough shifting or even complete failure of the gearbox.
  
• Track tension and undercarriage wear: The tracks and undercarriage of older machines like the Clark 35 AWS are subject to wear from constant use. Misaligned or worn-out tracks can affect the machine's mobility and efficiency.
  

Troubleshooting Transmission and Drivetrain Issues
Start by inspecting the clutch for wear and adjusting or replacing it if necessary. Check the gearbox and transmission fluid levels, and ensure the fluid is clean and at the proper level. Finally, inspect the tracks and undercarriage components, adjusting the tension and replacing any worn-out parts to ensure smooth movement.
The Restoration Process: Key Steps
Restoring a 1969 Clark 35 AWS to working condition involves several stages, each requiring attention to detail and the right tools and parts. The restoration process can be broken down into the following steps:

1. Disassembly and Inspection
   

The first step in restoring the machine is to disassemble key components and conduct a thorough inspection. This includes checking the engine, hydraulic system, transmission, and undercarriage for wear and tear. Documenting all issues will help prioritize repairs and replacements.

1. Engine Overhaul
   

Given the age of the machine, it’s likely that the engine will need a complete overhaul. This involves cleaning or replacing the fuel system components, inspecting the pistons and valves, and ensuring the cooling system is in good working order. If necessary, the engine may need to be re-bored or have new piston rings installed.

1. Hydraulic System Refurbishment
   

After addressing any leaks and replacing worn parts, the hydraulic system should be flushed to remove any contaminants. New seals, hoses, and filters should be installed to restore full hydraulic function. Testing the hydraulic pumps and valves will also help ensure optimal performance.

1. Transmission and Drive Train Rebuild
   

Rebuilding the transmission may involve replacing worn-out gears, clutch components, and seals. The undercarriage components, such as the tracks, sprockets, and rollers, should also be inspected and replaced as needed to restore the machine’s mobility.

1. Final Assembly and Testing
   

Once all repairs and replacements are complete, the machine should be reassembled and thoroughly tested. It’s important to ensure that all systems are functioning properly before putting the machine back into service.
The Rewards of Restoring Classic Equipment
Restoring a classic machine like the Clark 35 AWS can be a rewarding experience. Not only does it allow operators to preserve a piece of history, but it can also extend the life of the equipment for years to come. The restoration process offers an opportunity to learn more about the engineering behind these machines and to experience the satisfaction of bringing an old piece of equipment back to life.
Real-World Lessons from Restoration Projects
Many operators who have undertaken restoration projects on the Clark 35 AWS report the satisfaction of using machinery that has been meticulously brought back to life. One operator shared that restoring the hydraulics of the machine required a lot of patience, but after cleaning and replacing parts, it was a joy to see the loader perform as good as new. Others have found success in sourcing parts from specialized suppliers or even from other Clark models, which has helped them avoid lengthy downtimes.
Conclusion: Keeping the Legacy of the Clark 35 AWS Alive
The 1969 Clark 35 AWS may not be as fast or efficient as modern machinery, but its rugged reliability and historical value make it a prized possession for restoration enthusiasts. With the right tools, expertise, and patience, it’s possible to restore this vintage crawler loader to its former glory, ensuring it remains a valuable asset for years to come. The process of restoring classic equipment teaches us not only the importance of maintaining machinery but also the value of preserving the history behind the machines that have shaped industries.