7 John Deere D140 Problems and Quick Fixes

John Deere D140 Problems

There I was, relying on my trusted John Deere D140, expecting the usual robust performance when it suddenly sputtered to a halt.


I was among the unexpected 18% of owners who’ve faced issues with this model. If you, like me, depend on the D140 for your lawn or farm, you need to read on.

In the upcoming sections, I’ll share the common problems that turned my reliable machine into a headache and how knowing them could save you from frustration and costly repairs.

Join me, and let’s keep your green machine running smoothly.

John Deere D140 Problems

  1. Transmission Problems
  2. Starter Problems
  3. Engine Problems
  4. Fuel Problems
  5. Electrical issues
  6. Steering problems
  7. Vibrates excessively

1. John Deere D140 Transmission Problems 

The transmission issue is a common problem in most John Deere lawn tractors. The problem makes the pulley spin without turning the wheels.

This makes mowing difficult since the tractor moves slower than you expect. In some cases, interrupted or broken transmission could cause transmission issues.

It makes the tractor move at a hesitant pace. So when you notice that your lawn tractor cannot retain adequate speed or pull up small hills, it points to a transmission problem.


  • When the tractor moves slower, check the fuel levels and the engine. If the fuel level and the engine are ok, the problem is with the transmission system.
  • When the transmission system’s fluid viscosity and levels are hampered, it fails to transfer movement. So it may require that you replace the fluid. Unfortunately, you cannot replace the fluid, so buying a new transmission system is the only solution.

Related: John Deere 4066r transmission problems

 2. John Deere D140 Won’t Start

Check the electrical outlet or battery power if the tractor fails to start after pulling the starter button.

If the battery and the electrical outlets are fine but fail to start when you pull the button, the starter could have an issue.

The tractor may refuse to start if the spark plug is worn out or the carburetor is wrongly adjusted.

Similarly, clogged fuel lines make it difficult for the fuel to flow to the combustion chamber, so the mower will not start when you pull the starter.

In addition, if the throttle cable is worn out, the tractor will experience starting issues.

Thus, besides the battery, the spark plug, and clogged fuel lines, the tractor may not start if the gasoline is stale or the wires in the starter are damaged.


  • Connect a voltmeter to a solenoid starter’s battery terminal to test the battery. If the battery is faulty, you will need to replace it.
  • If the carburetor is wrongly adjusted, adjusting it could help correct the problem.
  • Replace worn-out throttle cables.
  • If the electrical wires are damaged, check and replace them.
  • If the starter has a problem, inspect and change the defective parts.

See: John Deere x330 problems.

3. John Deere D140 Engine Problems

If the mower has Engine problems, it will not follow the commands you give it. This may happen if there is a disruption in the engine mechanism, poor fuel or troublesome fuel pumps.

Any disruption in the mechanism makes it fail. Also, the engine could lose power as a result of overheating.

Overheating happens when the premix gets corrupted or the engine oil is too low. As a result, it makes it hard for the engine to start or run as it should.

If the gas mix is old or the gas is oxidized, the engine loses power, which disrupts the engine mechanism and results in engine problems.


  • If the gas mix is old, consider replacing it. Also, ensure to use gas with less than 10% ethanol. Ethanol-free gas is the best so if you have access to it, use it.
  • A faulty premix could result in engine problems. So to solve it, you may need to drain the gas tank, clean it, and flush out the dirt.
  • Fix the pump and replace the poor fuel.

4. John Deere D140 Fuel Problems

Fuel problems could be caused by a cracked fuel hose, faulty fuel pump, or bad fuel.

Also, accumulated dirt in the primary fuel tank could create a blockage and make it difficult for fuel to move to the combustion chamber.

Also, too much fuel choke is likely to lead to wastage and lead to fuel issues.


  • A fractured gasoline hose could lead to fuel issues. So, if there is, you may need to replace it with a new one. But installing a new horse could be difficult if you have never installed one. Therefore, start by installing the hose to the valve cover at the open end of the base before installing the other end.
  • For blockage problems, remove the hose to allow the fuel to move freely. Blow air into the fuel line to test if it is blocked. Once you see the gas flowing, reinstall the hose. But if the problem persists, drain the existing fuel and check if it has gone bad. Keep an eye on how the fuel trickles down. If the trickling is uneven, the gas is bad and could be the cause the problem. In such a scenario, you only need to replace the fuel to help solve the problem.
  • Consider replacing the air filter.

5. John Deere D140 Electrical Problems

The John Deere 140 tractor could have many electrical issues. Some of the issues may spread out to the starter resulting in a faulty electrical system.

In particular, the spark plugs will likely experience problems you must fix if you want the tractor to operate normally.


  • You can fix the spark plug issue by wiggling it free from the engine and using a wrench or pliers to unclasp it.
  • Use sandpaper to remove debris and dirt from the spark plug.
  • If the spark plug is rusty, replace it with a new one.

6. John Deere D140 Steering Problems

After months of good service, your John deere tractor may get difficult to steer. A loose bolt or worn-out bushings could cause this problem.

Worn-out bushings make engaging the gears difficult. Yet easy gear engagement is necessary for easy steering. Therefore, if the bushings are worn out, it becomes difficult to steer the tractor.

Of course, there are many other causes of steering problems. They include worn-out traction-driven belts, malfunctioned drive sheaves, and won out bench cutting blades.


  • Since there are many causes of steering problems, choose the correct solution to solve the issue. If the steering is too loose or too tight, identify the workout parts and replace them. You may install a new belt and replace the bushings or bolts.
  • If you replace the gears and the bushings but still experience the problem, consider replacing the whole sector plate.


7. John Deere D140 Vibrates Excessively

Mowing with a John Deere d140 is enjoyable if the tractor is in tip-top condition. However, after mowing hundreds of kilometres of grass, you will start feeling that the vibration is too much.

The causes of such vibration could be a worn-out sheave or belt. Also, the tractor may vibrate when the blades are out of balance or if the belt is misaligned.

Other causes include worn-out engine mounting bolts, a bad pulley bearing, unbalanced mower blades, a bad clutch, or a worn deck belt.

In addition, a damaged spindle bearing and collection of debris in the mower could lead to excessive vibration.


  • Check and replace worn-out or defective components such as bad clutch and worn-out engine mounting bolts.
  • Inspect and align the belt or the pulley.
  • If the blades are out of balance, you must balance them to reduce vibrations.
  • Cleaning the sheaves and decks will reduce clogging and eliminate vibration.

John Deere d140 Problems & Troubleshooting

John Deere D140 Transmission ProblemsPulley spins without turning the wheels– Check fuel levels and engine. If okay, the issue is with the transmission system. Replace the transmission system if fluid viscosity and levels are hampered.
John Deere Starter Problems– Electrical outlet or battery power- Worn-out spark plug- Incorrectly adjusted carburetor- Clogged fuel lines- Worn-out throttle cable- Stale gasoline or damaged starter wires– Test the battery using a voltmeter and replace if necessary.- Adjust the carburetor.- Replace worn-out throttle cables.- Check and replace damaged electrical wires.- Inspect and change defective parts of the starter.
John Deere D140 Engine ProblemsDisruption in engine mechanism- Poor fuel or troublesome fuel pumps- Overheating due to corrupted premix or low engine oil- Old or oxidized gas mix– Replace old gas mix with gas containing less than 10% ethanol or use ethanol-free gas.- Drain and clean the gas tank, flush out dirt, and fix the premix.- Repair or replace faulty fuel pumps.- Address overheating issues by maintaining proper premix and engine oil levels.
John Deere D140 Fuel ProblemsCracked fuel hose- Faulty fuel pump- Bad fuel- Accumulated dirt in primary fuel tank- Excessive fuel choke– Replace cracked fuel hose.- Clear blockages by removing and blowing air into the fuel line.- Replace or refill fuel if it has gone bad.- Consider replacing the air filter.
John Deere D140 Electrical ProblemsFaulty electrical system due to various issues, including spark plug problems– Check and tighten spark plug connections.- Clean spark plugs using sandpaper or replace them if rusty.
John Deere D140 Steering ProblemsLoose bolt- Worn-out bushings- Worn-out traction-driven belts- Malfunctioned drive sheaves- Worn-out bench cutting blades– Replace worn-out bushings, bolts, or belts as necessary.- Install new belts and replace the whole sector plate if needed.
John Deere D140 Vibrates ExcessivelyWorn-out sheave or belt- Blades out of balance- Misaligned belt- Worn-out engine mounting bolts- Bad pulley bearing- Unbalanced mower blades- Bad clutch- Worn deck belt- Damage spindle bearing- Debris in the mower– Replace worn-out or defective components such as the clutch and engine mounting bolts.- Inspect and align the belt or pulley.- Balance the mower blades.- Clean the sheaves and decks to remove debris.

Bonus – John deere d140 blades won’t engage

There could be a few mischievous culprits behind this issue. First up, check that sneaky mower deck engagement lever – make sure it’s properly hooked up for action.

Another troublemaker might be the misaligned or damaged drive belt, keeping those blades from having a whirlwind romance. Oh, and keep an eye out for any quirky behavior from the blade engagement switch and wiring.

And those worn-out pulleys? They’re like the bad boys of blade engagement. Replace them to restore harmony in your mowing kingdom.

Preventive Measures and Maintenance Tips

aintaining your John Deere D140 is key to keeping it running smoothly and reliably. Here are some maintenance tips to keep your trusty steed in top-notch condition:

  1. Keep it clean: Regularly clean the mower deck, engine, and other components to prevent dirt and debris buildup, which can affect performance.
  2. Check the oil: Regularly check the engine oil level and quality. Change the oil as per the manufacturer’s recommendations to ensure optimal lubrication.
  3. Spark plug TLC: Inspect and clean the spark plug regularly. Replace it if worn out or damaged to maintain a healthy ignition system.
  4. Don’t forget the air filter: Keep it clean or replace it if needed. A clogged air filter can restrict airflow and lead to reduced engine performance.
  5. Sharp blades for a clean cut: Regularly sharpen and balance the mower blades to ensure a clean and even cut. Dull blades can strain the engine and result in an uneven lawn appearance.
  6. Tend to the tires: Check the tire pressure regularly and ensure they’re properly inflated. Uneven tire pressure can affect the tractor’s stability and maneuverability.
  7. Fuel freshness matters: Use fresh fuel and avoid using fuel with excessive ethanol content. Stale or contaminated fuel can cause starting and running issues.
  8. Follow the maintenance schedule: Refer to the owner’s manual for the recommended maintenance schedule. Adhering to it will help you stay on top of routine tasks like oil changes, filter replacements, and overall inspections.


What are the main problems with John deere d140?

Although the John Deere 140 has great looks, the tractor is not exempted from problems that afflict mowers in its category. But the main problems you must grapple with include engine and transmission problems. John deere tractor shutting off is also another common issue.

What engine does the John Deere d140 have

John Deere D140 is fitted with a 22 HP Kohler K321AS engine. This is a powerful engine with a displacement of 512cc31.27ci. The engine has a massive torque that enhances the mower’s capability even when cutting long grass in hilly areas.

How should you store John Deere d140 when not in use?

Before you store the mower outside, you must siphon the gas from the tank. The gas contains corrosive ethanol, which could damage the carburetor if left in the tank. But before you siphon off the gas, add a fuel stabilizer in the tank and run the mower so that you distribute the gas through the system. Turn off the mower, let it cool, and siphon the gas from the tank.

Final thoughts on John Deere D140 problems

Undoubtedly, cutting grass could be an enjoyable exercise if you use the right mower. So if you can fix john deere d140 problems, then the JD140 mower could be the best option for you.

D140 is an ideal tractor for mowing a large compound since it has a 22-horsepower engine with a huge working torque.

Moreover, it comes with a rolled lip 48-inch mower deck that gives it the strength it needs to cut stubborn grass.