6 Most Common John Deere L120 Problems and Effective Fixes (2024)

The John Deere L120 features a powerful engine, smooth transmission, and easy-to-use controls, which make it a popular choice for homeowners with large lawns.

It has a cutting width of 48 inches, which allows for efficient mowing of larger areas. Despite these features, the L120 is prone to a few issues. The most common John Deere L120 problems are starting issues, transaxle problems, Worn-out hydro pump, excess smoke production, transmission problems, and abrupt stops.

We’ve taken the time to explore these issues and find simple, quick fixes. Read on.


  • 1 Problematic Starts
  • 2 Transaxle Problems
  • 3 Worn-out Hydro Pump
  • 4 Smoke Production
  • 5 Abrupt Stops
  • 6 John Deere L120 Transmission Problems
  • 7 John Deere L120 Review
  • 8 Conclusion

Problematic Starts

Hard starting is the most prevalent John Deere l120 problem. Your John Deere l120 won’t crank due to a faulty battery, dirty oil, little oil, and a defective spark plug and recoil.

Old fuel is the primary cause of clogging. Fuel breaks down after some time, leaving behind a solid residue responsible for blocking. This mainly affects the fuel filter and lines.

Blocked fuel filters and lines prevent sufficient air flow, making starting your tractor difficult. It’s advisable to regularly clean fuel residues in the filters and lines to avoid clogging.

Your tractor’s battery is its primary energy source. As such, any battery defects will lead to a problematic start. The battery’s voltage shouldn’t read below 12.7 volts. Always recharge before reaching this voltage to avoid inconveniences.

Overused spark plugs and broken recoils cause starting difficulties. You should replace spark plugs after every one hundred hours for improved efficiency. Check the recoil for damaged parts and fix them immediately if possible.

Transaxle Problems

Transaxle leaking is a prevalent complaint among John Deere l120 owners. This issue causes severe damage to the tractor’s hydro pump and general functionality. Low oil levels are the primary causes of transaxle issues, and a surging feeling is the first sign of this problem.

To fix transaxle issues, remove the transaxle from the tractor, then drain and clean it. Afterward, refill the tank with new oil and ensure it reaches about one inch from the vent’s plug hole. You shouldn’t worry about overfilling the tank, as leaking from the top is harmless to the tractor.

Low-viscosity oils are the most preferable for John Deere tractors due to their cooled air engines. A good example is Hy-Gard oil.

The john deere l120 transaxle is impossible to service. According to the manufacturer, you should replace it in case of internal damage.

Worn-out Hydro Pump

If your tractor crawls after starting, high chances are that its hydro pump is spoilt. This is because John Deere hydro pumps wear out fast.

A faulty hydro pump can’t pump hot oil sufficiently, leading to a constricted tractor movement. The most predominant sign of this issue is a noisy pump, indicating strain.

To prevent this inconvenience, constantly monitor the tractor’s hoses, oil levels, and connectors for early detection.

Smoke Production

Smoke production is one of the most prevalent John Deere l120 problems. Although this issue may be alarming, especially to new owners, fixing it is easy and won’t cost you an engine replacement if dealt with immediately.

The L120 lawn tractor produces smoke when the ratio of oil to air in their systems is high. Smoke production happens due to clogged air filters, excess crankcase oil, little engine oil, and internal engine problems.

Clogged air filters, a result of debris and dirt build-up, curb sufficient airflow in the tractor. Excess oil in the crankcase exerts superfluous pressure on the engine and eventually flows into the cylinder, while low oil levels cause the engine to strain, producing excess heat.

Cleaning clogged air filters and draining excess oil should fix your tractor. You should also refill the tractor if the problem results from little oil. However, it’s advisable to take the machine to a mechanic in case of engine problems.

Abrupt Stops

John Deere l120 tractors are prone to stopping after running for hours. This issue results from working on wet grounds, which causes the tractor’s engine to strain. Lifting the tractor’s deck improperly when cutting dense grass may also lead to this issue.

Another reason for your tractor to stop working is a faulty spark plug. Change this gadget religiously, after every 100 hours, to avoid problems.

A damaged tractor blade will cause the tractor to shut down. Faulty blades lead to excessive vibrations, which trigger stalling.

A dull blade means the engine has to work harder, leading to an unexpected shut-off. Always ensure that the mower’s blade is in tip-top condition before starting work.

In case of prolonged and frequent shut-offs despite applying the tips above, take the machine to a mechanic, as the problem could be internal and significant.

John Deere L120 Transmission Problems

Transmission issues are among the most prevalent John Deere L120 problems. You are likely to experience JD l120 transmission problems at some point. Primary causes of this issue include old hydraulic oil, low oil levels, and a faulty drive belt and tensioner pulley.

A faulty drive belt causes pump problems, which can be critical. Replace it immediately in case of wearing out, fraying, or cracking.

To fix a faulty tensioner pulley, grease the arm and replace the pulley. Old and low oil levels don’t lubricate the hydraulic system sufficiently, leading to transmission difficulties. Change the hydraulic oil and monitor its levels regularly to prevent this issue.

John Deere L120 Review

After examining John Deere l120 issues, it’s now time to look at a complete review of this lawn tractor. Despite its small size, the John Deere l120 is packed with impressive attributes. It features infinite gears you can control from the foot pedals, promoting smooth operation.

Built with 18 inches turning radius and 4×2 2WD chassis, the John Deere l120 is ideal for lawns with small grass patches requiring cutting. Its top speed of 8.8km/h makes it perfect for small and large gardens. The JD l120 operates on the Briggs and Stratton 40 or CV 40 gasoline engines, making it highly reliable.


The JD l120 lawn tractor is susceptible to several problems. The leading John Deere l120 problems are smoke production, transaxle leaking, problematic starts, and running issues. Fix your tractor using the tips in this article to avoid passing out on its benefits.

6 Most Common John Deere L120 Problems and Effective Fixes (1)


Hello! My name is Chris, and I am the founder of Yard Floor. When I was a toddler, my family had a lush green lawn. I was at the center of caring for and maintaining this lawn and even proceeded to take an associate’s Degree in landscaping. I am here to share my years of experience with you – be it repairing your mower/tractor or caring for your lawn.

6 Most Common John Deere L120 Problems and Effective Fixes (2024)


What is the average life of a John Deere lawn mower? ›

The average residential mower is used for 1-2 hours per mow with 35 cuts per year. Based on that usage, a lower-quality line of residential mowers is expected to last 450-500 hours, while a John Deere residential lawn mower will last around 1,000-1,500 hours.

How many hours should a John Deere tractor last? ›

The average lifespan of a tractor is 4,000 or more hours. Low hours on a tractor are pretty much anything less than where the warranty runs out. If you are buying a used tractor, then consider the hours in comparison to what the warranty covers in terms of hours.

How often should you service your John Deere riding mower? ›

Every lawn tractor and riding lawn mower needs a tune-up at least once a year. It's an easy task that'll take you 30 minutes or less. To make things even easier, TriGreen Equipment has Home Maintenance Kits for every model of John Deere Zero-Turn Mower, riding lawn mower, and lawn tractor.

What is high hours on a John Deere mower? ›

When I had my mowing business I had two F725 John Deere mowers that had over 2500 hours when I sold the business. Typically a 1000-1500 hrs is getting to be considered higher hrs. Myself when they get close to 800-1000 hrs they are getting where you are going to spend money.

Is it worth repairing a lawn mower? ›

If you are looking at a large issue with the engine or hydraulics, you should seriously consider buying a new mower. A repair of that size can come close to the price of a new unit. However, most other problems are fairly minor, and our mower repair teams can fix them quickly!

Is 500 hours a lot for a riding mower? ›

How Many Hours Should A Riding Mower Last? Most riding mowers last between 500-700 hours, although some can run for as much as 1,000 hours if cared for and maintained properly.

How many hours should a hydrostatic transmission last? ›

The hydraulic fluid and filter(s) should be changed as per the manufacturer's service schedule. With maintenance as per the recommended service schedule, an HST transmission should last around 500 hours.

Which tractors last the longest? ›

The Tractor Brand

Some companies construct their tractors with higher-quality materials and designs, which leads to the models lasting longer. Kubota tractors, for example, tend to offer a higher-than-average lifespan of 4,500 to 5,500 hours.

What is the most reliable John Deere tractor? ›

Considered one of the most reliable tractors ever made, the 4020 was produced from 1963-1972 and was popular among farmers due to its power and durability. The John Deere 4020 is a popular tractor that was produced by the American company John Deere.

What is included in a riding mower tune up? ›

Riding Mower Tune-Up in 5 Steps

Change the oil and replace the oil filter. Replace the spark plug. Replace the air filter. Replace the fuel filter.

How often should I change spark plugs on riding mower? ›

For lawn mower spark plugs, the maximum lifetime from manufacturers is two years. While this is the maximum lifetime, it is not the ideal lifetime. For your engine to remain at optimum performance, it is recommended to replace your spark plugs once a year or after 30 engine hours.

How often should you grease a John Deere lawn mower? ›

Greasing your mower's spindles may not need to happen as often as you might think. Even with regular use of your mower, you may only need to grease the spindles once a month. If you mow professionally, you may need to grease the spindles every other week or so.

What is a weakness of John Deere? ›

Weaknesses. Dependence on Agricultural Market Cycles: Deere & Co's performance is closely tied to the cyclical nature of the agricultural sector. Fluctuations in commodity prices, farm incomes, and overall economic conditions can significantly impact equipment sales.

How many hours between oil changes on a John Deere riding mower? ›

John Deere recommends you check your oil level before each use and to change your oil once a season. That's about every 50 hours of lawn tractor use.

What does the L mean on John Deere? ›

E - This letter lets you know it is a basic tractor with few extra features. L - This final letter specifies it is set up as a low profile - low clearance tractor.

Do John Deere mowers hold their value? ›

Resale Value

We have several customers that have traded in their mower and attachments that are decades old and still receive up to several hundred dollars for them. That's pretty amazing considering what they originally paid plus all the hours they put on them!

Can a lawn mower last 20 years? ›

It is possible for a lawn mower to last 20 years or more with proper maintenance and care. However, it's not very common for a lawn mower to last that long.

Is 2000 hours a lot for a lawn mower? ›

That is a lot. If you figure normal 40 hour week is 2040 hours a year. Then that mower has basically run nonstop for nearly a year of its life. Considering the average time to mow a lawn at about 1/2 hour, that machine has started and stopped 4,000 times.

How often should you buy a new lawn mower? ›

5-10 Years Old. If you have managed five or more years out of your current riding mower, it is time to start planning on picking up its replacement. The repairs tend to become more frequent and more costly.


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