Removing the Gasoline Starting Engine from a John Deere Model 60: A Practical Guide

[MikePhua]

Background on the John Deere Model 60 and Its Starting System
The John Deere Model 60, a two-cylinder tractor produced in the early 1950s, often came equipped with a gasoline starting engine (sometimes called a “pony motor”) to start the main diesel engine. This system was common in the mid-20th century before the widespread adoption of electric start systems for large diesel engines. The gasoline starting engine’s job was to warm and spin the diesel engine fast enough for compression ignition to take over.
The JD 60’s gasoline starting engine drives the diesel engine via a clutch and gear assembly. Removing this starter requires care, mechanical understanding, and often, creative workarounds due to its compact and aged design.
Tools and Preparations for Removal
Before beginning removal, ensure the following:

• The diesel engine is cool and the tractor is parked safely on level ground.
  
• Disconnect the battery and shut off all fuel lines.
  
• Drain fluids if necessary (especially coolant and oil that might spill during removal).
  
• Have appropriate lifting tools (engine hoist or crane) ready, as the starter is heavy.
  
• Prepare a clean area for disassembly with labeled containers for bolts and parts.
  

Key Tools and Equipment:

• 3/4" drive socket set with extensions and universal joints
  
• Large pry bars
  
• Torque wrench
  
• Penetrating oil
  
• Jack or engine hoist
  
• Shop manual (recommended but not mandatory)
  

Step-by-Step Disassembly Process
1. Remove the Hood and Side Panels
This allows better access to the engine compartment. Removing the hood often requires detaching the fuel tank or shifting it backward slightly.
2. Disconnect Fuel and Electrical Lines
Disconnect the fuel line to the gasoline starting engine and any electrical wires to avoid snagging or damage. Label the wires if you're unfamiliar with the routing.
3. Remove the Radiator (Optional but Helpful)
Although not strictly necessary, many operators find it far easier to remove the radiator, fan shroud, and fan itself. This provides more room to maneuver and lift out the starting engine.
4. Unbolt the Starter Engine Mounts
There are typically four mounting bolts at the base of the starting engine. These bolts may be corroded, so penetrating oil is your friend here. Use a breaker bar if needed, and avoid stripping the heads.
5. Disconnect the Drive Coupling or Gear Assembly
The gasoline starting engine connects to the diesel engine through a clutch and gear system inside the housing. This connection must be carefully disengaged. Often, the engine needs to be slid straight out to avoid damaging the drive gear teeth.
In some versions, there’s a sliding coupler or spline shaft that must align properly during removal and later reinstallation. If this is stuck, some gentle persuasion with a rubber mallet may help—but never use excessive force.
6. Lift Out the Gasoline Engine
Using an engine hoist, gently lift the gasoline engine out of its cradle. Use lifting straps or chains attached to designated lifting points. Maintain steady tension and have a second person guide the engine to prevent it from catching on wiring or brackets.
Special Notes on JD 60 Starter Removal

• The upper rear bolt is often the hardest to access and may require a universal joint socket with an extension bar.
  
• Some older machines have shims under the mounts; these must be kept in order for reassembly.
  
• If the starting engine hasn’t been removed for decades, you may find rust locking the engine in place even after unbolting it. Heat, careful tapping, or even a jack under the engine mount may help.
  

Common Complications and Fixes
Frozen Bolts and Rusted Mounts
Many older tractors suffer from corrosion in the starter cradle. Soaking with penetrating oil and gentle heat (via torch or heat gun) may be required.
Damaged Drive Coupler
If the drive coupler is worn or broken, sourcing a replacement can be a challenge. However, parts can still be found through vintage tractor clubs, machine shops, or specialty restoration outfits.
Starter Engine Won’t Slide Out
If the engine hangs up on one side or won’t pull out smoothly, double-check that all bolts and couplers are disengaged. A common issue is missing a hidden bolt or interference from the flywheel cover.
Modern Alternatives and Historical Context
By the late 1950s, electric starters became the standard due to improvements in 12V and 24V battery systems. Still, some farmers and collectors prefer the gasoline starting engines for their reliability in extremely cold climates. The “pony motor” earned its nickname because it was small and lively, galloping the bigger diesel engine to life.
Interestingly, the idea of a small engine starting a larger one wasn’t unique to tractors. Early aircraft and military vehicles often used similar methods, including explosive cartridge starters (like those on old British jets), showing how engineers in different fields approached the same problem of getting large engines to crank reliably in all conditions.
Tips from the Field

• Always photograph every step of disassembly for future reference.
  
• Use anti-seize compound during reinstallation to make future servicing easier.
  
• Rebuilding or replacing worn engine mounts can greatly reduce vibration and noise.
  
• If replacing the starter engine with an electric system, ensure proper alignment and voltage regulation to avoid damage to the flywheel ring gear.
  

Conclusion
Removing the gasoline starting engine from a John Deere Model 60 is a task that requires mechanical finesse, preparation, and a respect for vintage machinery. While time-consuming, the process is a rite of passage for many restorers and offers a hands-on education in mid-century diesel starting systems. For those passionate about preserving history, the effort is more than worthwhile—it's a direct connection to the ingenuity of past generations.