John Deere GX335 Problems

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The issues you may encounter with John Deere GX335 are often common with all lawn mower models. You can fix these problems if you are aware of the causes and carry out a few simple repairs.

In this article, I share 5 common John Deere GX335 problems you might experience and DIY troubleshooting tips for fixing them.

John Deere GX335 Problems, Causes, And Solutions


Before I go into details, let’s have a look at some common problems and possible solutions.


Possible Solutions

1. Starting problems
  • Replace the spark plug 
  • Clean the carburetor and blocked fuel lines
  • Replace clogged fuel filter 
  • Charge the battery
  • Replace faulty starter
2. Hydrostatic transmission problems 
  • Top up insufficient hydraulic fluid
  • Drain out contaminated fluid 
  • Replace a faulty pump
  • Replace the fluid filter if dirty
  • Purge the system
3. Fuel pump problems
  • Replace the fuel pump 
4. Mower problems
  • Clean the cutting deck
  • Increase deck height
  • Replace the belt
  • Sharpen mower blades
5. PTO Problems
  • Replace damaged solenoid
  • Replace blown fuse
  • Find and repair malfunctioning safety switch
  • Replace faulty PTO switch

1. Starting Problems

Starting problems are quite common with the John Deere GX335 mower. It may manifest as a hard start, a no-start situation, or an engine that starts and then shuts down immediately.



First, check the spark plug. Test the plug for spark and replace it if defective or worn out.

Inspect the fuel system for dirt and clogging. Drain out stale fuel and replace the fuel lines and fuel filter if they are clogged with old fuel debris.

A dirty carburetor may result in a hard start or no start situation. Soak the carburetor in a carburetor cleaner to unclog the jets and remove debris.

Next, check the starter to see if it is functioning properly. If it isn’t, you will need to replace it.

Finally, test the battery with a multimeter. Recharge or replace it if it is producing less than 12 volts.

2. Hydrostatic Transmission Problems


In a hydrostatic transmission, the pump itself drives the engine using the fluid flowing through numerous moldable hoses.

The issues you may encounter with the JD GX335 include system overheating, low fluid pressure, and fluid temperature issues.


  • Insufficient hydraulic fluid
  • Water in the hydraulic system
  • Faulty pump
  • Dirty hydraulic fluid filter
  • Air trapped in the hydraulic system


If the hydraulic system overheats, top up the fluid level. Then, check for water in the fluid. If the fluid color appears white or dark brown, replace it.

Bleed the system to remove any trapped air, and change the oil filter if it is dirty or clogged.

Check the hoses and pulse for fluid leakage and replace the faulty components once or is found.

A faulty pump will also cause issues with the system. Have the pump disassembled by a professional technician and replace any damaged components. 

3. Fuel Pump Problems


The fuel pump of your John Deere GX335 may develop some issues along the line.

A sensor is built into the fuel pump of a John Deere GX335 tractor, helping to regulate the fuel flow into the carburetor.

The engine could abruptly shut off or backfire if the sensor is not functioning as it should, which could happen if the fuel pump is not supplying the engine with enough fuel to run.


  • Faulty fuel pump sensor
  • Damaged/worn fuel pump


First, ensure that fuel is flowing to the pump. Once you’ve established that you’re getting enough fuel to the fuel pump, remove the fuel line from the carburetor and place it in a container.

Next, start the fuel flow. If you see a stream of fuel coming out of the fuel line, it means your fuel pump is working properly. If not, the fuel pump is defective.

The pump contains check valves that can wear down over time and cause the pump to malfunction. Replace the pump if it is worn or defective.

4. Mower Problems

John Deere mowers frequently experience mowing issues, which can manifest in various ways.

Your John Deere GX335 might be cutting unevenly, skipping sporadic lawn patches, or the blades might not be doing a proper job of cutting the grass.


  • Cutting deck obstruction
  • Low cutting deck height
  • The mower blade is bent or blunt
  • Slack or damaged belt
  • Dirty pulley
  • Fast ground speeds


The mower deck should first be cleaned to get rid of any obstructions. Removing caked-on grass and debris will require the use of a water hose, scraper, or pulley knife.

The cutting height deck should then be adjusted if it is too low, especially if your grass is thick and tall. 

Examine the blades. Are they bent? Is it unbalanced? Adjust, sharpen, or replace the blade if necessary.

A malfunctioning belt and pulley system can also result in mowing problems. It is advisable to replace the belt if it is loose or glazed.

Clean, examine and replace any damaged components on the idler and pulley springs.

Cutting grass quickly may lead to uneven cuts and other mowing problems. Use slower speeds when mowing.

5. PTO Problems

Some common PTO problems users of this John Deere tractor experience include: PTO not engaging, the clutch won’t engage, and the PTO shaft not turning.


  • Blocked hoses or fittings
  • Faulty connections
  • Damaged solenoid
  • Blown fuse
  • Malfunctioning safety switch
  • Faulty PTO switch


Check for clogs in all the hoses and fittings, and fix/replace them accordingly. 

Then, check the battery voltage and see if the solenoid is receiving and sending charge. If the battery is producing less than 12 volts, recharge it. Replace the solenoid if faulty.

Also, one of the safety switches may be damaged and cause PTO failure. For example, the switch below the seat can get clogged with debris and start malfunctioning. Check all the safety switches and replace any faulty ones.

Look for the fuse that attaches the PTO clutch assembly to all of the electrical cablings. Replace it with a new fuse with the same ampere rating as the original if the fuse appears to have blown.

Finally, replace the PTO switch if it is faulty or damaged.

What Majority Of Users Think About The John Deere GX335

From customer reviews, it is a fantastic tractor with a wide range of applications. The machine has power and is simple to use whether you are cutting grass, spreading fertilizer, or moving gravel.

The JD GX335 is also very skilled at many other tasks around the garden and outside in addition to cutting your grass. On the front of the lawnmower, you can attach snow blowers, snow blades, thatchers, and front blades. 

On the back, you can attach well over 20 additional different types of tools, ranging from tillers to rakes.


Your John Deere GX335 may develop starting, transmission, fuel pump, PTO, or mower issues.

You can identify the cause of these issues and fix your mower by following the instructions and troubleshooting guides outlined in this article.

Frequently Asked Questions 

1. What engine does John Deere GX335 use?

It uses a Kawasaki FH601V, 2-cylinder, air-cooled, engine.

2. How much engine power does John Deere GX335 have?

The John Deere GX335 engine has a horsepower of 20HP.

3. Is John Deere GX335 reliable?

Yes, the John Deere gx335 is a reliable mower and can last for a very long time if properly used and maintained.

4. How much does a John Deere GX335 weigh?

The John Deere gx335 weighs about 309 kg(683 lbs).