Restoring and Maintaining the Hough HA Payloader with Confidence

[MikePhua]

The Hough Legacy and the HA Series
The Hough HA Payloader was part of a pioneering lineage of wheel loaders developed by Frank G. Hough Company, which was later acquired by International Harvester in the 1950s. Hough was among the first to commercialize the term “Payloader,” referring to a front-end loader capable of lifting and transporting bulk material with speed and precision. The HA model, produced in the 1960s and early 1970s, was a mid-size machine built for construction, quarrying, and municipal work.
With an operating weight of approximately 15,000 pounds and powered by a gasoline or diesel inline-six engine, the HA featured a torque converter transmission, planetary final drives, and a robust hydraulic system. Though production ceased decades ago, many HA units remain in service today, especially in rural yards and small fleets where mechanical simplicity is valued over electronic sophistication.
Core Systems and Service Priorities
The HA Payloader is built around four primary systems:

• Powertrain: Engine, torque converter, transmission
  
• Hydraulic: Pump, control valves, lift and tilt cylinders
  
• Steering: Hydraulic orbital valve, steering cylinders
  
• Braking: Air-over-hydraulic or mechanical drum brakes
  

Terminology annotation:

• Torque converter: A fluid coupling that multiplies engine torque and allows smooth gear engagement.
  
• Planetary final drive: A gear system that increases torque at the wheels while reducing speed.
  
• Orbital valve: A hydraulic steering control unit that directs fluid to the steering cylinders based on wheel input.
  

Routine service should focus on fluid integrity, seal condition, and mechanical wear. The HA’s systems are accessible and modular, allowing most repairs to be performed with basic tools and mechanical know-how.
Hydraulic System Insights and Troubleshooting
The HA’s hydraulic system operates at approximately 2,000 psi and uses a gear-type pump mounted directly to the engine. Common issues include:

• Slow lift or tilt response due to pump wear
  
• Leaking cylinder seals from age or contamination
  
• Sticky control valves from varnished fluid
  
• Air in the system causing jerky motion
  

Solutions:

• Replace hydraulic fluid every 500 hours or annually
  
• Use ISO VG 46 or 68 hydraulic oil depending on climate
  
• Rebuild cylinders with modern seal kits
  
• Flush the system with a low-viscosity cleaner before refilling
  

In one case from Iowa, a farmer restored his HA’s lift function by replacing the pump with a modern aftermarket unit and retrofitting the control valve with new spools sourced from a salvage yard.
Transmission and Torque Converter Behavior
The HA uses a single-stage torque converter feeding into a two-speed transmission. Symptoms of wear include:

• Sluggish acceleration
  
• Delayed gear engagement
  
• Transmission overheating
  
• Fluid discoloration or burnt smell
  

Recommendations:

• Drain and replace transmission fluid every 1,000 hours
  
• Use Type F or Dexron III depending on converter design
  
• Inspect cooler lines for blockage or leaks
  
• Replace worn clutch packs and seals during rebuild
  

In British Columbia, a contractor extended the life of his HA by installing an auxiliary transmission cooler and switching to synthetic fluid, reducing operating temperature by 20°F.
Steering and Brake System Considerations
The HA’s steering is hydraulic, with a simple orbital valve and dual cylinders. If steering becomes heavy or erratic:

• Check for low hydraulic fluid
  
• Inspect cylinder seals and rod wear
  
• Test orbital valve for internal leakage
  

Brakes may be mechanical or air-assisted. Common issues include:

• Weak braking due to worn shoes or drums
  
• Air leaks in booster system
  
• Contaminated brake fluid
  

Solutions:

• Rebuild brake cylinders and replace shoes
  
• Bleed air system and test compressor output
  
• Use DOT 3 or DOT 4 brake fluid as specified
  

In Nebraska, a restoration team converted an HA’s brakes to a modern hydraulic disc setup using parts from a retired grader, improving stopping power and serviceability.
Parts Sourcing and Documentation Challenges
Finding original parts for the HA can be difficult, but solutions include:

• Salvage yards specializing in IH and Hough equipment
  
• Rebuilding components with universal seal kits and bushings
  
• Fabricating brackets and linkages using service manual diagrams
  
• Networking with vintage equipment forums and clubs
  

Service manuals are essential for torque specs, fluid capacities, and exploded diagrams. While original manuals are rare, scanned copies and reprints are available through collector networks and specialized vendors.
Preventative Maintenance and Longevity Strategy
To keep an HA running reliably:

• Grease all pivot points monthly
  
• Inspect hoses and belts quarterly
  
• Monitor fluid levels weekly
  
• Replace filters every 250 hours
  
• Store under cover to prevent UV and moisture damage
  

In Texas, a rancher added a magnetic drain plug to his HA’s transmission and caught early signs of gear wear before failure. He rebuilt the unit during off-season and avoided costly downtime.
Conclusion
The Hough HA Payloader is a testament to mid-century engineering—simple, rugged, and built to last. With proper care, thoughtful upgrades, and access to service documentation, these machines can continue working for decades. Whether used for loading gravel, clearing snow, or moving hay, the HA remains a reliable partner for those who understand its systems and respect its legacy.