Reviving a Classic: Starting Troubles and Restoration of the John Deere 310A Backhoe

[MikePhua]

Reviving a Classic: Starting Troubles and Restoration of the John Deere 310A Backhoe
Inherited Iron: The Challenge Begins
When a Wyoming landowner inherited a John Deere 310A backhoe—likely a pre-1976 model with a 3-cylinder diesel engine—he faced a common but daunting issue: the machine cranked but refused to start. Despite replacing the battery and using ether, the engine showed no signs of firing. Fuel reached the injector pump and lines, but the injectors didn’t spray, and the engine cranked sluggishly under load.
This scenario is familiar to many who acquire older equipment. Machines like the 310A, built in the late 1970s, are known for their durability but can suffer from neglected maintenance, fuel system degradation, and electrical gremlins after years of dormancy.
Hydraulic Load and the Destroke Solenoid
One key insight came from seasoned mechanics: the hydraulic pump must be destroked during startup. If the solenoid responsible for this fails or is disconnected, the starter must turn both the engine and the hydraulic pump—resulting in slow cranking and no ignition. A disconnected wire near the pump hinted at this issue, and replacing the solenoid became a priority.
In cold climates, operators often manually destroke the pump or turn the steering wheel during cranking to reduce hydraulic resistance. This trick, passed down through generations of diesel mechanics, can mean the difference between a dead start and a roaring engine.
Fuel System Diagnostics and Governor Woes
The fuel system on older John Deere models, particularly those with JDB rotary injection pumps, is prone to internal failure. A common culprit is the rubber governor damper disk, which deteriorates over time, sending debris into the pump and disrupting fuel delivery. One user discovered black rubber bits inside the pump’s inspection cover—a telltale sign of damper failure.
Rebuilding the pump is possible for skilled hands, but timing and linkage alignment are critical. Misadjusted governor linkages or incorrect timing can cause rough running, blue smoke, and throttle unresponsiveness. In Virginia, a mechanic reinstalled his pump after resealing it, only to find the engine stuck at half throttle due to a misaligned governor spring.
Compression and Cold Starts
Diesel engines require air, fuel, and compression. If ether doesn’t provoke even a sputter, compression may be lacking. A compression test can reveal worn rings, valve issues, or head gasket failures. For the 310A’s 3-cylinder engine, typical compression should exceed 300 PSI. Significant variation between cylinders may indicate internal damage.
In Nova Scotia, a winter operator shared a tip: flip the clutch pedal’s mechanical lever to disengage the transmission during cold starts. This reduces load on the starter and improves cranking speed—especially useful when the clutch plate risks rusting together from disuse.
Manuals, Diagrams, and Community Wisdom
Finding accurate diagrams for the 310A can be challenging. Fortunately, resources like the John Deere TM1158 Technical Manual and parts schematics offer detailed guidance on hydraulic, electrical, and mechanical systems. These documents are essential for tracing fuel lines, identifying solenoids, and understanding the pump’s internal layout.
In 2025, Deere enthusiasts launched a community archive to preserve legacy manuals and share restoration stories. One contributor documented a full rebuild of his 310A, including pump overhaul, clutch adjustment, and electrical rewiring—transforming a forgotten relic into a reliable workhorse.
Conclusion: Persistence Pays Off
Restoring a John Deere 310A is a journey through diesel diagnostics, hydraulic quirks, and mechanical intuition. From solenoid mysteries to governor spring adjustments, each fix brings the machine closer to life. For those willing to learn and listen—to both the engine and the community—the reward is not just a running backhoe, but a deeper connection to the legacy of American iron.