John Deere 4120 Overview

What engine specifications and horsepower does the John Deere 4120 offer?

The John Deere 4120 is equipped with a 2.4L (148.9 cubic inches) 4-cylinder turbocharged diesel engine that is liquid-cooled.

It delivers a gross engine power of about 43.1 horsepower (32.1 kW).

The tractor’s Power Take-Off (PTO) power is rated at 35 horsepower (26.1 kW).

The engine model associated with the 4120 often references the John Deere 4024T.

Additional engine specs include:

Bore and stroke: 3.386 x 4.134 inches (86 x 105 mm)

Torque around 95 lb-ft

Liquid cooling system

It offers either a 12-speed manual or hydrostatic transmission.

This engine setup supports the tractor’s role as a compact utility machine suitable for various tasks.

What is the current market price range for a used John Deere 4120?

The current market price range for a used John Deere 4120 typically spans from approximately $18,500 to $32,900 USD.

Listings vary depending on the tractor’s year, hours of use, condition, and included features.

For example, some recent listings show prices around $24,500 to $32,900 USD for models from the mid to late 2000s, with lower-hour machines generally commanding higher prices.

Some specific examples from online listings include used 2004 models priced around $14,995 to above $30,000 depending on condition and hours, though more common used prices in 2024-2025 range from mid $18,000s to low $30,000s.

This price range reflects the John Deere 4120’s strong reputation for reliability and utility in the compact tractor category.

Which problems are commonly reported with the John Deere 4120?

The most commonly reported problems with the John Deere 4120 include:

Cold starting issues: Difficulty starting in cold weather, which can be addressed by troubleshooting PTO switches and installing intake warmers.

Ignition problems: Related to electrical system malfunctions.

Hydrostatic transmission problems: Issues with PTO clutch, solenoids, sensors, or O-rings causing malfunction in the hydrostatic drive.

Smoking from exhaust: Indicative of engine or fuel system problems.

Failure under load: The tractor may refuse to move unless running at higher RPMs due to load management or potentiometer issues.

Sensor issues: Faulty or broken sensors requiring replacement.

Fuel injector problems: Needing injector replacement.

Steering concerns: Unresponsive steering, excessive play, or difficulty making turns, often linked to steering linkage or hydraulic system problems.

Hydraulic system issues: Fluid leaks, contamination, overheating, and wear of seals or hoses.

Transmission challenges: Gear shifting problems, slipping gears, or strange noises during gear changes.

Engine troubles: Starting problems, power loss due to clogged filters or spark plugs, and overheating related to coolant system faults.

Addressing these requires routine inspections, troubleshooting sensors and electrical components, maintaining hydraulic fluid and cooling systems, and replacing worn parts when needed.[1][2]

This comprehensive list aligns with multiple user reports and expert troubleshooting guides for the John Deere 4120 tractor.

Conclusion

The John Deere 4120 is favored for its balance of power, compact size, and versatility, making it suitable for small farms, landscaping, and light to moderate utility tasks.

This overview is synthesized from manufacturer data and detailed specifications found in multiple authoritative tractor databases and listings.