9 Most Common Kubota GR2120 Problems and How To Fix Them

The Kubota GR2120 is a compact utility tractor designed for small-scale agricultural, lawn, and light construction work. It has a 20-horsepower diesel engine and can be equipped with mowers, tillers, and snow blowers.

Although using these tractors is enjoyable, you may face some occasional difficulties. So, what are the common Kubota GR2120 issues? The most common Kubota GR2120 problems are transmission issues, engine drawbacks, battery problems, glide steer complications, overheating, hard starts, smoke, and problematic handling.

Is the Kubota GR2120 reliable? Keep reading as we break down problems with this tractor and effective fixes.

Kubota GR2120 Transmission Problems

Inadequate transmission oil and aeration are the primary causes of Kubota GR2120 transmission problems.

Transmission oil lubricates the systems’ parts, allowing smooth operations. Inadequate oil strains gears and other transmission parts, resulting in malfunctions. Monitor the oil levels and refill the reservoir to the ‘Full’ mark to prevent these issues.

Excess air reduces the system’s hydraulic pressure, which regulates transmission functions. Purge the system to get rid of all the excess air.

You should check for loose seals and nozzles and replace them with new ones. Faulty nozzles and seals get loose during operations, allowing air into the system.

Engine Problems

The leading Kubota GR2120 engine problems are insufficient power and refusing to idle. Your tractor’s engine may produce insufficient power due to a plugged air filter or inadequate fuel flow.

The engine requires sufficient air for complete combustion and smooth operations. Air filters prevent dirt from getting into the tractor’s system by sieving it all out. These elements clog with time thanks to dirt build-up, hindering airflow through the system and restricting power production. Clean your tractor’s air filters regularly to prevent these inconveniences.

Fuel is essential for power production. Inadequate fuel causes the engine to strain, leading to complications. Regularly monitor the fuel levels and refill the fuel tank if depleted.

If your tractor’s engine doesn’t idle, the high chances are that the fuel filter is clogged. Plugged fuel filters restrict adequate fuel flow to the engine. This makes it challenging to produce the power required for idling. Fuel filters easily block due to fuel carbon residue. Clean them regularly to curb these issues.

Battery Issues

Kubota GR2120 battery issues might arise due to the following.

  • Problematic starters
  • Poor charging
  • Bad connections
  • Rapid electrolyte level drops

Starters may refuse to function due to a low battery charge or an expired battery life. A low battery charge doesn’t supply enough power. Ensure the battery’s charge is above 12 volts before setting off to avoid these inconveniences.

Batteries get damaged and malfunction after prolonged use. Monitor these tractor parts closely and replace them with new ones immediately after they show aging signs.

The leading cause of battery charging problems is an expired life. Dead batteries don’t absorb power efficiently, reducing their recharging capabilities. Replace your tractor’s battery immediately after it expires to curb these Kubota GR2120 problems.

Damaged terminals hinder effective electrical connections. To fix this problem, replace corroded terminals with new ones. If the terminals misbehave due to dirt build-up, cleaning them is enough to revive them.

If your tractor’s battery electrolyte level drops rapidly, chances are that there are pinholes or cracks in the electrolyte cells. Replace damaged components with new ones to solve this problem for good.

Kubota GR2120 Glide Steer Problems

The Kubota GR2120 glide steer may occasionally refuse to make tight turns. Disorientation is the leading cause of the Kubota GR2120 glide steer problems. Adjusting glide steers will solve this problem immediately.

Pack your tractor on level ground and turn the engine off before adjusting the glide steer. Proceed to jack it up and straighten the front tire using the steering wheel. Ensure you steer the front tires till they form an angle “A” 0.35 rad ( 22°). Use a protractor to confirm the angle.

To adjust the glide steer, move the rod back and forth till there’s free play. Adjust both the right and left rods for effective results.


Your Kubota GR2120 tractor may overheat due to the following reasons.

  • Low engine oil
  • Clogged cooling fins
  • Plugged air flow paths

Oil lubricates the engine, guaranteeing smooth operations. When insufficient, the engine parts strain to produce power. This results in the production of excess heat. Regularly monitor the engine oil levels and refill the oil pan to the recommended level to avoid this problem.

Cooling fins pull away heat from the engine but collect dirt and clog with time. Plugged fins cause the motor to retain heat, increasing the tractor’s temperatures. Clean the tractor’s cooling fins regularly.

Airflow paths allow cool air to reach the engine and regulate its temperatures. However, they collect dirt with time and block, restricting smooth flow. Clean your tractor’s air flow paths regularly.

Starting Problems

Kubota GR2120 starting problems might arise due to the following reasons.

  • Clogged fuel filters
  • Air in the fuel system
  • High oil viscosity
  • Discharged battery

Fuel filters sieve out dirt from the fuel. These elements clog due to dirt build-up after prolonged use. This restricts smooth fuel flow to the engine, resulting in difficult starts. Regularly clean the fuel filters to curb these Kubota GR2120 problems.

Air in the fuel system reduces the fluid pressure, reducing sufficient fuel flow to the engine. To fix this problem, bleed the system until no more bubbles are coming up.

High oil viscosity delays fuel injection. This, in turn, strains the engine, resulting in hard stars. The wrong oil thickens and gets viscous during the winter. Switch the oils, depending on the seasons, to curb this issue.

Engines rely on the battery’s power to ignite. A low battery charge stresses the engine. Always charge the battery and ensure it has more than 12 volts before starting operations.

You should also check the battery’s charging system and replace it if damaged. A faulty charging system isn’t effective in transmitting power to the battery.

Smoke Emission

Your Kubota GR2120 tractor might sometimes produce black, blue, or white smoke. Black smoke results from a clogged air filter. Plugged air filters restrict clean air from reaching the engine, resulting in incomplete combustion and black smoke. Clean filters regularly to solve this problem.

Excess oil is the primary cause of blue or white smoke. Engines burn off the extra oil, producing fumes. Avoid overflowing the oil pan. Always refill the oil pan to the recommended level.

Leaking also results in bluish-white smoke. Oil may drop on a hot tractor component and burn off, producing smoke. Check for blown-off head gaskets and damaged cylinder rings and replace them immediately.

Problematic Handling

Handling your Kubota GR2120 may be challenging due to low transmission oil or uneven tire pressure. Transmission oil lubricates the tractor moving parts and produces sufficient hydraulic pressure for easy handling and steering.

Inadequate oil gives the moving parts a hard time during operations, leading to problematic handling. Monitor the transmission oil levels and refill the reservoir to the recommended level.

Uneven tire pressure causes alignment issues, pulling the tractor to one side. Always confirm the tire pressure on all tires before driving your Kubota GR2120.

It’s advisable to add pressure according to the tractor’s recommended PSI. Excess pressure reduces the tires’ contact with the ground, increasing slipping chances. Low tire pressure increases lateral and forward drag steering effects, making handling the tractor strenuous.

PTO Issues

Some Kubota GR2120 tractor owners complain about PTO issues. Your tractor’s PTO might malfunction due to these reasons:

  • Faulty clutch packs
  • Damaged control valves
  • Worn-out seals

Clutch packs regulate energy transmission to auxiliary tractor parts that don’t produce power. When defective, they result in major PTO malfunctions. Replace them if faulty to avoid these complications.

Control valves are crucial for effective PTO functions. However, valves malfunction with age. Monitor them closely and replace them immediately after they show aging signs.

Control valve seals wear out and get loose with time. Check them and switch them with new ones if damaged.

Are Kubota GR2120 Problems a Deal Breaker?

Kubota GR2120 issues aren’t necessarily a deal breaker. These tractors are pretty reliable, and regular maintenance keeps them working optimally. Whether or not the mentioned problems are a deal breaker depends on factors such as the issue’s severity, repair cost, and the tractor’s intended use.