10-21-2025, 02:25 PM
Quick answer
The Case 680H backhoe loader may feel sluggish on inclines due to torque converter behavior, engine RPM issues, or transmission settings. A stall test and throttle response check can help isolate the problem, especially when gauges are inoperative.
Case 680H background and mechanical profile
The Case 680H is a mid-sized tractor-loader-backhoe (TLB) introduced in the late 1970s by Case Corporation, a company with a long-standing reputation in agricultural and construction equipment. The 680H was powered by a 336 cubic inch diesel engine, typically producing around 75–80 horsepower. It featured a torque converter transmission and was designed for heavy-duty excavation, trenching, and material handling.
The 680H was part of Case’s broader 680 series, which evolved through multiple iterations (680B, 680C, 680E, etc.), each improving hydraulic flow, operator comfort, and drivetrain efficiency. The 680H was known for its robust digging power, but some operators noted sluggish travel speed, particularly on inclines.
Symptoms of power loss and field observations
In one case, an operator reported that while the digging functions of the 680H were strong, the machine struggled to climb hills—even in first gear. On flat ground, performance was acceptable but still felt underpowered. This raised concerns about whether the issue was normal for the model or indicative of a mechanical fault.
Key diagnostic steps and stall test procedure
A senior technician recommended a stall test to evaluate the torque converter and engine output. The procedure is as follows:
Common causes of sluggish travel performance
Several factors can contribute to poor travel speed or climbing ability:
Operators familiar with the 680H often note that while the machine is capable, it lacks the travel speed of newer hydrostatic or powershift models. One contractor recalled using a 680H on a steep Oregon property, where it could only climb in first gear at full throttle. After adjusting the throttle linkage and replacing a clogged fuel filter, performance improved noticeably.
Conclusion
The Case 680H remains a capable backhoe loader, but age-related wear and mechanical misadjustments can lead to sluggish travel performance. A methodical approach—starting with a stall test and basic linkage checks—can reveal whether the issue lies in the engine, torque converter, or transmission. With proper diagnostics and maintenance, the 680H can continue to serve reliably in demanding environments.
The Case 680H backhoe loader may feel sluggish on inclines due to torque converter behavior, engine RPM issues, or transmission settings. A stall test and throttle response check can help isolate the problem, especially when gauges are inoperative.
Case 680H background and mechanical profile
The Case 680H is a mid-sized tractor-loader-backhoe (TLB) introduced in the late 1970s by Case Corporation, a company with a long-standing reputation in agricultural and construction equipment. The 680H was powered by a 336 cubic inch diesel engine, typically producing around 75–80 horsepower. It featured a torque converter transmission and was designed for heavy-duty excavation, trenching, and material handling.
The 680H was part of Case’s broader 680 series, which evolved through multiple iterations (680B, 680C, 680E, etc.), each improving hydraulic flow, operator comfort, and drivetrain efficiency. The 680H was known for its robust digging power, but some operators noted sluggish travel speed, particularly on inclines.
Symptoms of power loss and field observations
In one case, an operator reported that while the digging functions of the 680H were strong, the machine struggled to climb hills—even in first gear. On flat ground, performance was acceptable but still felt underpowered. This raised concerns about whether the issue was normal for the model or indicative of a mechanical fault.
Key diagnostic steps and stall test procedure
A senior technician recommended a stall test to evaluate the torque converter and engine output. The procedure is as follows:
- Warm up the machine to operating temperature.
- Place the transmission in high gear.
- Apply the brakes fully to prevent movement.
- Push the throttle to full open.
- Observe the engine RPM during this “stalled” condition.
- No-load full throttle RPM: approximately 2400 RPM
- Stalled RPM with brakes applied: around 2100 RPM
Common causes of sluggish travel performance
Several factors can contribute to poor travel speed or climbing ability:
- Low engine RPM: Faulty throttle linkage, governor issues, or fuel delivery problems can reduce available power.
- Torque converter malfunction: A worn or locked converter may not transmit power efficiently.
- Declutch valve mispositioned: If the declutch switch is engaged, it can prevent power from reaching the transmission.
- Transmission wear: Internal clutch packs or planetary gears may be slipping under load.
- Hydraulic drag: Excessive hydraulic load or pump inefficiency can sap engine power.
- Repair or replace non-functional gauges to monitor RPM and temperature accurately.
- Perform a full stall test and compare results to factory specifications.
- Inspect throttle linkage and ensure full travel from idle to full throttle.
- Check declutch switch position and functionality.
- Examine transmission fluid condition and pressure.
- If needed, consult a Case 680H service manual for detailed specifications and adjustment procedures.
Operators familiar with the 680H often note that while the machine is capable, it lacks the travel speed of newer hydrostatic or powershift models. One contractor recalled using a 680H on a steep Oregon property, where it could only climb in first gear at full throttle. After adjusting the throttle linkage and replacing a clogged fuel filter, performance improved noticeably.
Conclusion
The Case 680H remains a capable backhoe loader, but age-related wear and mechanical misadjustments can lead to sluggish travel performance. A methodical approach—starting with a stall test and basic linkage checks—can reveal whether the issue lies in the engine, torque converter, or transmission. With proper diagnostics and maintenance, the 680H can continue to serve reliably in demanding environments.
