When John Deere introduced the 3520 in the mid-2000s, it had been lauded as a small tractor with enormous capabilities. From tilling to mowing or plowing to discing, the machine can perform any farming job you throw at it.
But although this tractor is well-known for its versatility and durability, it can still experience common problems that many tractors of its caliber have experienced over time. Many owners complain about the engine stalling at start-up, loss of power, and even a hydraulic system failure.
The good news is that most of these problems can be fixed without too much technical expertise. With that said, let’s run through the five most common John Deere 3520 problems encountered, along with their symptoms, causes, and possible solutions.
Quick Table for John Deere 3520 Problems, Reasons, Symptoms, and Solutions
The chart below overviews the top five John Deere 3520 problems, outlining their symptoms and short solutions.
|1||The Tractor Won’t Start||● The tractor turns over but doesn’t start|
● The engine won’t turn over at all
● It won’t start even if the motor starts
● It starts but stalls out immediately
|● Ensure adequate fuel.|
● Check the fuel lines for damage or kinks, clean filters.
● Replace spark plug wires.
● Replace ignition and relay switches.
● Replace the starter solenoid.
|2||Sudden Loss of Power||● Abrupt drop of engine speed|
● The panel glows warning lights
● Increase of speed before shut-offs
● No response to throttle input
|● Replace the start switch or fuse.|
● Flush out contaminants from the fuel tank.
● Remove obstructions from the fuel line.
● Check the circuit wiring for corrosion and damages.
|3||Hydraulic System Failure||● Abrupt oil leakage|
● Sudden rear lift stalling
● Malfunctioning pressure regulator
● The engine won’t keep running
● Slow or jerky movements
|● Replace the EOP sensor.|
● Refill or replace as fluid.
● Clean the clogged hydraulic pump.
● Replace worn bearings.
● Repair or replace the O-rings/gaskets.
|4||Lift Arms Will Not Lower Completely||● The lift arms will only drop to a certain point before stopping.|
● The lift arms will not drop at all.
|● Replace the hydraulic cylinders and adjust the lift arms to a lower position.|
● Have the tractor serviced for any leaks.
● Replace the relief valve.
|5||Turbocharger Failure||● Whining sound from the turbocharger|
● Low power levels at high RPMs
● Heavy exhaust smoke
● Decreased fuel efficiency
● Burning oil smell from the exhaust pipe
|● Remove carbon buildup.|
● Replace the worn bearings.
● Replace any leaking seals, gaskets, and/or o-rings.
● Ensure the turbocharger is appropriately lubricated.
● Replace the turbocharger entirely.
5 Common Problems with John Deere 3520, Reasons, Symptoms, and Solutions:
Continuing our in-depth discussion about the common John Deere 3520 problems, let’s look at how you can effectively solve them.
1. The Tractor Won’t Start
No matter what type of machinery you’re working with, whether an industrial-sized excavator or a compact tractor like the John Deere 3520, there’s nothing more irritating than when your equipment won’t start. If your tractor doesn’t start, it can mean anything from a low battery to an issue with the fuel injection system—and no matter what is wrong, it’s going to hold up your work.
The following signs can indicate a failed engine start.
- The tractor turns over but doesn’t start
- The engine is not turning over at all
- The starter motor runs, but the tractor still doesn’t start
- The tractor starts but stalls out immediately
Your tractor’s engine may fail to start for several reasons, including:
- A fuel issue
- Faulty spark plug wires/connections
- Faulty ignition switch or relay switch
- Bad battery or dead battery cell
- The starter solenoid has failed
- A problem with the electrical system
Try the following troubleshooting methods when your John Deere 3520 has a problem starting.
- Ensure your tractor has adequate fuel.
- Check the fuel lines for damage or kinks, clean filters, and ensure no blockage at the lift pump.
- Check spark plug wires and connections, ensuring there are no damaged spots. If you find bad wires, replace them.
- Check the ignition switch and relay switch for damage. If either of these parts appears damaged, replace it immediately.
- Replace the starter solenoid.
2. Sudden Loss of Power
Many complaints have been about a sudden loss of power with John Deere 3520 machines. This problem can lead to your tractor’s sudden shut-down in the middle of a job. It can also lead to problems with your equipment’s performance and may even damage other components of your tractor.
Your 3520 tractor may indicate a sudden loss of power by showing the following signs.
- The engine speed dorps or stops working abruptly
- Warning lights glow up within the panel
- Engine speed increases just before it shuts off
- While running, the engine stops and then restarts after a few minutes
- The machine does not respond to throttle input
Possible causes of this problem include one or more of the following.
- A faulty start switch or blown fuse
- Inadequate air supply to the engine due to dirty air filter or clogged muffler screen
- A contaminated fuel tank
- Inadequate fuel supply due to the faulty fuel pump and/or fuel filter
- A defective or loose wiring system
Once you’ve identified the problem, follow these steps accordingly.
- Replace any malfunctioning start switch or fuse.
- Check the fuel tank for water or debris and flush out any contaminants with diesel fuel and a wire brush if necessary.
- Check fuel lines for obstructions like dirt or other foreign material; clear out any debris you find.
- Check all wiring in the starting circuit for damage. Be sure to check the battery terminals for corrosion and the starter motor for signs of wear.
3. Hydraulic System Failure
A hydraulic system failure in your John Deere 3520 is a severe problem that can lead to a loss of power steering, brakes, and other hydraulic functions. This can be a serious safety issue if the tractor is being operated at the time of the failure. To resolve this problem as quickly as possible, you must understand its symptoms and causes before troubleshooting it.
Below are the telltale signs of a failed hydraulic system.
- Oil leakage from different parts of the machine
- Sudden stalling of the rear lift
- Malfunctioning pressure regulator
- The engine starts but won’t stay running
- The machine has jerky and/or slow movement
You may experience a hydraulic system failure on a John Deere tractor for the following reasons.
- Failed Engine Oil Pressure (EOP) sensor
- Low fluid level or poor fluid quality
- Fluid contamination by water or fuel (due to a leak in the engine)
- A faulty hydraulic pump or the pump has a clogged suction filter
- Worn bearings on the hydraulic pump
Following identification of possible causes troubleshoot hydraulic problems as follows.
- Replace the EOP sensor.
- Check fluid level and quality, and refill or replace as needed.
- Clean the clogged hydraulic pump or replace it if necessary.
- Check for worn bearings and replace them with new ones.
- Repair or replace the O-rings/gaskets.
4. Lift Arms Will Not Lower Completely
If your John Deere 3520 lift arms do not lower completely, it can lead to several problems. You may not be able to reach the full depth you need for cultivating or tilling, and it can make attaching implements like cultivators and plows difficult, even impossible. Here are the symptoms, causes, and possible solutions.
These two symptoms clearly indicate this problem.
- The lift arms will only drop to a certain point, and then they will stop.
- The lift arms will not drop at all.
Your tractor may not lower its lift arms entirely because of the following issues.
- Lift arms are set too high.
- Lift arms have been operated while returning the tractor to a lower position.
- Operators have been performing some other tasks while lowering the lift arm.
- Hydraulic fluid levels are low (possibly from a leaking fitting).
- The relief valve is stuck open.
The lift arm lowering issue can be resolved by attempting these solutions.
- Replace the hydraulic cylinders and try to adjust the lift arms to a new, lower position
- Have the tractor serviced for any leaks in the hydraulic system
- If the above does not work, replace the relief valve
5. Turbocharger Failure
One of the common problems with a John Deere 3520 is turbocharger failure. This problem can make it difficult for the engine to start or run smoothly, and if left untreated, turbocharger failure can cause the engine to shut down unexpectedly or fail entirely.
The following signs indicate that your tractor’s turbocharger has failed.
- Whining sound from the turbocharger
- Low power levels at high RPMs
- Heavy exhaust smoke
- Decreased fuel efficiency
- Burning oil smell from the exhaust pipe
The John Deere 3520’s turbocharger can fail because of the following issues.
- Improper oil level (too high or too low)
- Foreign objects inside turbocharger system (lint from maintenance rags, etc.)
- Insufficient lubrication from lack of maintenance/oil changes or clogged oil pickup screen/filter
- Worn bearings allow for excessive play in shafts or wheels.
Proper maintenance is essential to resolve the turbocharger failure problem on your tractor. Here’s what you can do.
- Clean the turbocharger regularly to remove carbon buildup.
- Replace the worn bearings.
- Replace any leaking seals, gaskets, and/or o-rings.
- Ensure the turbocharger is appropriately lubricated at all times.
- Check the turbocharger for signs of damage and replace it if required.
We’ve put together answers to some common questions about the John Deere 3520 and related issues.
How do I adjust the steering on my John Deere 3520?
To adjust the steering on your John Deere 3520, first, adjust the front axle stops. Then turn the steering wheel all the way in one direction. Loosen the castle nut on the drag link and turn each tie rod one complete turn clockwise. Finally, turn the wheels back to a straight-ahead position and tighten the castle nut.
The lawnmower deck will not rotate in my John Deere 3520. How do I fix this?
The first and most important thing to do when this happens is turn off the mower and remove the key. This prevents you from accidentally starting the mower while working on it. Then, inspect the deck and make sure nothing obstructs it or gets caught in it. If there is, remove the obstruction, and the problem should be fixed.
My John Deere 3520 shift. What should I do?
If you have trouble shifting into gear, check your transmission fluid level. If it is low on fluid, add some until it reaches its proper level. Also, be sure your right-hand console’s lights are on and that your parking brake is engaged. You may also need to replace the shift fork and/or shift pins in your transmission.
What grade is John Deere hydraulic oil?
John Deere hydraulic oil is specified by the company as a 10W-30. The 10W-30 is a multi-grade oil that can also be used in place of a 5W-30, 15W-40, or 20W-50. This grade is recommended for use in temperatures above 40 degrees Fahrenheit (4 degrees Celsius).
Why does the battery of my 3520 discharge quickly?
The alternator may not be charging. Check the battery for a bad cell that is causing the alternator to work harder than usual. If your battery is old, it might be time for a replacement.
Although the John Deere lineup of tractors is extraordinarily diverse and offers a product for every scenario and budget, it should come as no surprise that the 3520 tractor isn’t without problems.
Luckily, finding solutions to the common John Deere 3520 problems is relatively easy. As outlined in this article, most can be resolved with some routine maintenance or a few quick repairs. However, if the issues escalate beyond your expectations, don’t hesitate to reach out to your local John Deere dealer.
Do you have any tips, advice, or further questions on this tractor? Let us know in the comments below!