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The Legacy of the Hough 65
The Hough 65 wheel loader was produced in the early 1970s by Hough, a division of International Harvester. Known for its rugged build and mechanical simplicity, the H65 was designed for mid-range earthmoving tasks, including quarry work, road maintenance, and material handling. With an operating weight of around 20,000 pounds and powered by a diesel engine mated to a torque converter transmission, the H65 was a staple in municipal fleets and private construction outfits.
Though Hough was eventually absorbed into Dresser Industries and later Komatsu, many of these machines remain in service or restoration due to their durable frames and rebuildable drivetrains. Sales records from the mid-1970s suggest that thousands of units were distributed across North America, particularly in the Midwest and Northeast.
Understanding the Torque Converter System
The Hough 65 uses a torque converter transmission, which relies on hydraulic fluid to transfer power from the engine to the wheels. Unlike manual clutches, torque converters allow for smooth acceleration and gear changes under load. The system includes:
Terminology Explained
In one case, a 1974 Hough 65 sat idle for over three years. After getting the engine running, the loader refused to move. The driveshaft stopped spinning when shifted into gear, suggesting that the transmission was engaging but not transmitting power. Several possibilities were considered:
In upstate New York, a retired quarry mechanic restored a Hough 65 that had been parked behind a barn for six years. After replacing the starter and flushing the fuel system, he discovered the loader wouldn’t move. The driveshaft stopped when shifted into gear, and fluid levels appeared normal. Upon inspection, the fiber coupler had disintegrated. He fabricated a replacement using a salvaged disc from a Hough H90 and restored drive function. The loader was later used to clear snow and haul gravel for a local trail project.
Recommended Restoration Steps
Saving a Hough 65 from the scrap yard is a rewarding challenge for any equipment enthusiast. With its robust frame and forgiving transmission, the loader can be revived with basic mechanical skills and attention to hydraulic integrity. Whether used for snow removal, grading, or hauling, the H65 remains a testament to mid-century American engineering.
The Hough 65 wheel loader was produced in the early 1970s by Hough, a division of International Harvester. Known for its rugged build and mechanical simplicity, the H65 was designed for mid-range earthmoving tasks, including quarry work, road maintenance, and material handling. With an operating weight of around 20,000 pounds and powered by a diesel engine mated to a torque converter transmission, the H65 was a staple in municipal fleets and private construction outfits.
Though Hough was eventually absorbed into Dresser Industries and later Komatsu, many of these machines remain in service or restoration due to their durable frames and rebuildable drivetrains. Sales records from the mid-1970s suggest that thousands of units were distributed across North America, particularly in the Midwest and Northeast.
Understanding the Torque Converter System
The Hough 65 uses a torque converter transmission, which relies on hydraulic fluid to transfer power from the engine to the wheels. Unlike manual clutches, torque converters allow for smooth acceleration and gear changes under load. The system includes:
- Torque converter housing mounted directly to the engine flywheel
- Transmission pump that circulates fluid through the converter
- Driveshaft connecting the engine to the transmission input
Terminology Explained
- Torque Converter: A fluid coupling that transmits engine power to the transmission.
- Flywheel Coupler: A flexible or fiber disc that connects the engine flywheel to the converter input.
- Transmission Sump: The reservoir where hydraulic fluid is stored and circulated.
In one case, a 1974 Hough 65 sat idle for over three years. After getting the engine running, the loader refused to move. The driveshaft stopped spinning when shifted into gear, suggesting that the transmission was engaging but not transmitting power. Several possibilities were considered:
- Failed flywheel coupler Fiber couplers can degrade over time, especially if exposed to moisture. A broken coupler would prevent torque transfer.
- Low or incorrect fluid The transmission and torque converter share a sump. Fluid must be checked while idling in neutral. Using hydraulic oil instead of Dexron ATF can affect performance.
- Clogged sump screen or filter Debris in the sump can restrict fluid flow, starving the converter and causing engagement failure.
- Pump failure The transmission pump mounted on the converter housing may have stripped gears or failed seals.
In upstate New York, a retired quarry mechanic restored a Hough 65 that had been parked behind a barn for six years. After replacing the starter and flushing the fuel system, he discovered the loader wouldn’t move. The driveshaft stopped when shifted into gear, and fluid levels appeared normal. Upon inspection, the fiber coupler had disintegrated. He fabricated a replacement using a salvaged disc from a Hough H90 and restored drive function. The loader was later used to clear snow and haul gravel for a local trail project.
Recommended Restoration Steps
- Check transmission fluid while idling in neutral
- Use Dexron III ATF or Universal Tractor Fluid (UTF) if compatible
- Inspect and replace the transmission filter located inside the left frame rail
- Remove the converter housing to inspect the flywheel coupler
- Flush the sump and clean the screen to restore fluid flow
- Replace transmission fluid every 500 hours
- Inspect coupler condition annually
- Monitor temperature gauges for converter overheating
- Store the machine under cover to prevent moisture damage
Saving a Hough 65 from the scrap yard is a rewarding challenge for any equipment enthusiast. With its robust frame and forgiving transmission, the loader can be revived with basic mechanical skills and attention to hydraulic integrity. Whether used for snow removal, grading, or hauling, the H65 remains a testament to mid-century American engineering.
