John Deere 40 Tractor (History & Spec Chart)
John Deere built the Model 40 from 1953 through 1955, between the Model M and Model 420. Its baseline specifications include a liquid-cooled, two-cylinder gasoline engine displacing 113.1 cubic inches, rated at 1,850 rpm, and a four-forward, one-reverse transmission. Exact dimensions and equipment depend on the tractor’s configuration, so verify its serial number before ordering parts or choosing an implement.
The Model 40 has a compact, purposeful look: two cylinders beneath a simple hood, with the stance and running gear shaped by the work it was built to do. That familiar profile can make two tractors seem alike, but a row-crop model, utility tractor, orchard configuration, or crawler may differ in ways that matter for parts and implements.
When I evaluate an older tractor, I start with identification rather than a parts catalog. A model name is a useful first clue, not proof that every specification or attachment will match. Below is a baseline guide to the Model 40, along with practical checks for safe operation and seasonal readiness.
John Deere Model 40 history and identification
The Model 40 was produced from 1953 through 1955. It followed the Model M and preceded the Model 420 in Deere’s lineup. Its short production run makes the serial number and the tractor’s configuration especially useful when you are checking parts, manuals, or equipment fit.
Before you buy a part or attach an implement, record the tractor’s serial number and identify its configuration. Compare that information with the correct operator’s or service manual. If a tractor has been modified, such as a change to its electrical system, note that too; its current equipment may not match its original factory setup.
John Deere 40 specifications
Specifications below are baseline figures for the Model 40, not a complete specification for every configuration. Confirm variant-specific details in the relevant manual. In particular, do not infer implement capacity, PTO speed, dimensions, or electrical polarity from the model name alone.
| Item | Baseline Model 40 specification |
|---|---|
| Production years | 1953–1955 |
| Engine | Two-cylinder, four-stroke gasoline |
| Cooling | Liquid-cooled |
| Displacement | 113.1 cu in (1.85 L) |
| Bore × stroke | 4.125 × 4.25 in |
| Rated engine speed | 1,850 rpm |
| Transmission | 4 forward gears, 1 reverse |
The figures describe the general model. They do not establish a safe load rating or confirm that a particular tractor has a specific hitch, PTO arrangement, or electrical system. A tractor’s condition also matters: wear, repairs, or past changes can affect how it operates today.
Many original Model 40 tractors used a 6-volt, positive-ground electrical system. However, a surviving tractor may have been converted. Check the battery, wiring, and charging components before connecting a charger or replacing electrical parts. Do not assume a modern 12-volt, negative-ground setup.
Model 40 configurations and implement fit
An implement is a tool attached to or driven by the tractor, such as a mower or other field equipment. Compatibility depends on the tractor’s actual hitch, PTO, ballast, and rated capacity, not just its model name. Verify these details against both the tractor and implement manuals before use.
| Configuration or item | What to verify | Why it matters |
|---|---|---|
| Row-crop, utility, orchard, or crawler | Serial number and configuration | Dimensions and running gear can vary |
| Hitch | Type, pins, and stated limits | The implement must connect and be supported correctly |
| PTO | Type, speed, engagement instructions, and guards | Implements must match the tractor’s drive setup |
| Ballast | Manual guidance and tractor setup | The right setup supports stable operation |
| Tires or tracks | Condition and configuration | Traction and safe handling depend on sound running gear |
Do not guess at a PTO speed or load limit. If the manuals do not clearly confirm a match, pause and consult a qualified Deere dealer or tractor service specialist. A connection that can be made physically is not necessarily a safe or suitable match.
Practical fitment scenarios
These examples are decision scenarios, not documented accounts of specific Model 40 owners. They show how I would work through common questions without assuming that every tractor is equipped the same way.
- A mower is offered with the tractor: First identify the tractor configuration. Then compare the mower’s required hitch, PTO type and speed, and operating instructions with the tractor manual. Check the guards and driveline before use.
- A replacement hitch pin seems close enough: Do not rely on appearance alone. Confirm the correct hardware and fit in the relevant manuals, and inspect the hitch for wear or damage.
- A battery charger flags an error: Check the battery voltage and ground polarity before connecting another charger. A charger intended for a 12-volt system may not suit an original 6-volt system; confirm the tractor’s current setup and follow charger instructions.
- A crawler and wheeled tractor appear to share a part: Verify the serial range and configuration. Similar model names do not establish that dimensions or parts are interchangeable.
The key step in each scenario is confirmation before purchase or use. That can prevent a poor fit, avoid damage, and reduce the risk of an unsafe setup.
Safe inspection and operation
Safe operation begins with the tractor parked on firm, level ground and its controls set as directed by the manual. Before starting, check critical systems, keep bystanders clear, and understand how the implement connects and operates. If steering or braking is questionable, do not run the tractor until the defect is repaired.
Before starting
- Inspect tires or tracks, steering, service brakes, clutch, and throttle return.
- Look for fuel and coolant leaks. Check fluid levels as directed in the manual.
- Check the drawbar, hitch pins, guards, and PTO shielding.
- Confirm that the implement’s hitch and drive requirements match the tractor.
- Keep people clear of the hitch, implement, and PTO area.
A failed brake or steering part can lead to loss of control, especially on a slope. Stop work if either system is not sound. Do not test a questionable tractor on a hill or rely on the transmission to stop it; service brakes must work independently.
Starting and working
- Park on firm, level ground. Disengage the PTO and implement, place the transmission in neutral, and set the brakes.
- Use the correct fuel and engine oil for the tractor’s serial range and conditions. Follow the manual’s instructions for starting controls.
- Start from the operator’s seat. Keep hands, clothing, and tools clear of moving parts.
- Let the engine warm at a moderate speed. Watch for abnormal oil pressure, temperature, noise, or leaks.
- Choose a low gear suited to the terrain and load. Avoid sudden turns, overloading, and side slopes.
- Engage the PTO only as the applicable manual directs. Keep shields installed and bystanders away.
Never tow from the axle, seat frame, or any point above the approved drawbar. Pulling from a high point can cause a rear overturn. Never approach or adjust a PTO-driven implement while the PTO is engaged or the driveline is moving.
Stopping
Lower the implement, disengage the PTO, shift to neutral, set the brakes, and shut down. Remove the key and allow hot parts to cool before inspection or service. If an implement must be worked on while raised, secure it with blocking as directed by its manual; never depend on hydraulics alone.
Maintenance and seasonal storage
The correct service settings and intervals depend on the tractor’s serial range and condition. Use the matching manual for ignition timing, valve clearance, carburetor settings, lubricants, capacities, and fastener torque. Avoid transferring settings from another engine or assuming that a modified electrical system follows the original wiring.
At the intervals in the manual, inspect engine oil, coolant, the air cleaner, fan belt, ignition parts, fuel lines, battery connections, and brakes. Repair leaks and defective brakes before returning the tractor to service. For implement work, check PTO and driveline guards, hitch hardware, tires or tracks, and ballast before each use.
For storage, clean and dry the tractor, lower the implement, and secure the machine against movement. Protect the battery and fuel system using procedures suited to the tractor’s electrical setup and the fuel in use.
Before seasonal operation, look for rodent damage, cracked fuel hoses, fluid leaks, tire deterioration, stuck controls, and brake problems. Test the tractor in a clear, level area before attaching or loading an implement. If the brakes or steering do not feel sound, stop and arrange repairs first.
Conclusion
A Model 40’s baseline specifications are useful for identification, but they are not enough to confirm parts or implement compatibility. Start with the serial number and configuration, then verify hitch, PTO, ballast, and service details in the correct manuals. A careful inspection and a controlled test on level ground are sensible first steps before seasonal work.
Frequently asked questions
This FAQ covers common identification, specification, and operating questions about the Model 40. The short answers provide a starting point, but the tractor’s serial number, configuration, condition, and manuals determine the details for a particular machine.
What years was the John Deere Model 40 made?
The Model 40 was produced from 1953 through 1955.
What tractor came before the Model 40?
The Model M preceded it. The Model 40 was later succeeded by the Model 420.
What engine does the Model 40 have?
Its baseline engine is a liquid-cooled, two-cylinder, four-stroke gasoline engine with 113.1 cubic inches (1.85 L) of displacement.
What is the Model 40’s rated engine speed?
The baseline rated engine speed is 1,850 rpm. Check the relevant manual for the tractor’s specific operating guidance.
How many gears does a Model 40 have?
The baseline transmission has four forward gears and one reverse gear.
Is every Model 40 the same configuration?
No. Model 40 tractors include different configurations, such as row-crop, utility, orchard, and crawler. Dimensions and equipment may vary.
Does a Model 40 have a 6-volt or 12-volt electrical system?
Many originals used a 6-volt, positive-ground system, but some tractors have been converted. Check the battery and wiring before charging or replacing components.
How do I know whether an implement fits?
Identify the tractor and verify the implement’s hitch, PTO type and speed, ballast needs, and rated capacity in the applicable manuals. Do not rely on the model name alone.
Can I use the transmission to stop the tractor?
No. The service brakes must be inspected and working independently. Do not operate the tractor if braking is questionable.
Where can I find exact service settings?
Use the operator’s or service manual that matches the tractor’s serial range. Do not assume another Model 40’s settings apply to yours.
(This article was written by one of our staff writers, Harrison Croft. Visit our Meet the Team page.)
