John Deere 5603 Problems (A Troubleshooting Handbook)

Have you been having problems with John Deere 5603? Looking for a dependable source of the solution? 

Since it is a highly facilitated tractor, it rarely causes severe problems. Therefore, you shouldn’t worry too much about it. On this topic, we have an entire article. 

Engine not starting, losing power, and overheating are the common John Deere 5603 engine problems.  You also may experience PTO hard engaging issues. Apart from that, in the transmission, you may find unusual sounds, hard gear shifting, etc. The majority of these problems can be fixed by yourself.

This is just an overview. Continue reading this article for more information.

John Deere 5603 Engine Problems

Problem Reason Solution
Engine won’t start  Faulty battery Jumpstart/replace your battery.
Fuel filter clogged Unclog fuel filter.
Engine power loss Dirty injector nozzle  Clean injector nozzle.
Engine suddenly shuts Fuel injection pump failure  Replace the injection pump.
Engine overheating Radiator core is dirty/damaged Replace/ Clean Radiator.

Problem 1: Engine Won’t Start

Sometimes you may find your John Deere engine is not starting. And there can be multiple reasons behind this problem. Let’s see what prevents the engine from starting. 

Reason 1: Faulty Battery

A faulty battery is one of the main reasons behind the engine starting issues. Because to start the engine battery supplies the electrical necessity.

But if the battery is drained or dead, then it can’t supply the necessary power to the engine to start it. As a result, the John Deere 5603 engine doesn’t start. 

Solution: Jumpstart/ Replace Battery

If the John Deere 5603 battery is out of charge, you need a jumpstart. You can perform a jumpstart by yourself. To do this, you just need to arrange the following tools: 

  • A fully charged vehicle/ battery
  • A jumper wire

Now, let’s start the proceedings:

  • Find out the battery trunk and open it. And after that, Connect the red cable with the positive terminal and the black cable with the negative terminal. 
  • In this step, you need to connect both batteries. Connect it carefully, paying attention to the positive and negative terminals of the battery.
  • After connecting both batteries by the jumper wire, jiggle the ignition switch. You’ll find your problem is solved. 

But if the battery is completely dead, you may need to replace the battery. It’ll cost around $100.

Reason 2: Clogged Fuel Filter

Clogged fuel filter is another reason why your John Deere 5603 may not start. If the filter is clogged, fuel can’t transmit properly to the engine. And for the lack of fuel, the engine can’t start.

Solution: Unclog the Fuel Filter

Unclogging the fuel filter is very simple. You just need to follow some simple steps to do this. Let’s see how to unclog the John Deere 5603 fuel filter.

  • First, lock the fuel transmission line. Then take the fuel filter out of the fuel line. 
  • Next, you must wash out all the debris and contamination properly. And after washing the filter, let it dry. 
  • Finally, set the filter as it was.

Problem 2: Engine Power Loss

You may find your John Deere 5603 is losing power suddenly. And for the lack of engine power, you can face a lack of performance. 

There are some reasons behind this problem. Let’s discuss those reasons here.  

Reason: Dirty Injector Nozzle

Dirty injector nozzles also prevent fuel from reaching the engine. The engine loses power as a result of a lack of fuel. 

And this is the reason why a dirty injector nozzle causes engine power loss. But there is a very simple solution to this issue. 

Solution: Clean the Injector Nozzle

To clean a tractor injector nozzle, Follow the steps below: 

  • First, you need to remove the nozzle from the tractor. 
  • In this step, scrub the nozzle to remove any dirt or debris using a small brush and diesel fuel or carburetor cleaner. Ensure the nozzle is thoroughly cleaned, paying particular attention to the holes. 

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  • Before reconnecting the nozzle to the tractor, rinse it thoroughly with clean water and let it dry completely.

Problem 3: Engine Overheating

A common problem with the John Deere 5603 tractor is engine overheating. There are several reasons why engines overheat.

Reason: Dirty/ Damaged Radiator

A dirty or damaged radiator can cause problems for your vehicle, as the radiator is responsible for maintaining the proper temperature of the engine coolant.

Dirty radiators can reduce coolant flow, resulting in overheating and engine damage. It is also possible for a damaged radiator to leak coolant.

Causing the engine to overheat and possibly causing injury if the coolant comes into contact with hot engine components.

Solution: Clean/ Replace the Radiator 

To fix a dirty or damaged radiator, you will need to take the following steps:

  • To clean a dirty radiator, use a garden hose or pressure washer to wash away any dirt or debris carefully. Make sure the radiator fins are not damaged.
  • Once the radiator is clean and in good condition, refill the coolant to the proper level and replace the radiator cap.
  • Start the engine and let it run for a few minutes to ensure that the radiator is functioning properly and that the engine is not overheating.

It may be necessary to replace or repair the radiator if it has been damaged. For minor damage, such as a small leak, you may be able to patch it with a radiator repair kit.

In the event of more severe damage, it is recommended that the radiator be replaced entirely. 

John Deere 5603 PTO Problems

Problem Reason Solution
PTO not engaging Faulty clutch pack Replaces clutch pack.

Problem: PTO (power take-off) Not Engaging

When the PTO (power take-off) on a John Deere 5603 tractor does not engage, power cannot be transferred from the engine to an attached implement. 

This is because PTO transfers power from the tractor’s engine to the PTO shaft, which in turn transfers power to the attached implement.

Reason: Faulty Clutch Pack

The most common cause of PTO not engaging is a faulty clutch pack. If the clutch pack on the tractor is faulty, it may not transmit enough torque to the PTO shaft, which prevents the PTO from engaging.

This may damage the machinery and prevent the attached implement from functioning properly.

Solution: Replace the Clutch Pack

A clutch assembly replacement can be a complex and delicate process, and it is important to do it correctly to prevent further damage.

It is best to seek help from a qualified mechanic if you are unsure how to fix a clutch pack.

John Deere 5603 Transmission Problems

The transmission is critical because the operator controls the tractor’s speed and direction.

It may be difficult to shift gears, the gears may not engage properly, or the tractor may not move at all if there is a problem with the transmission.

Problem Reason Solution
Unusual noise in the transmission Incorrect backlash  Adjust the backlash to the correct specification.
Hard gear shifting Low level of gear oil Refill gear fluid.

Problem 1: Unusual Noise in the Transmission

Occasionally, you may hear an unusual sound coming from your John Deere 5603 transmission. There can be several reasons behind this problem. 

Reason: Incorrect Backlash

It is possible for John Deere 5603 tractor transmissions with the incorrect backlash to develop problems and produce unusual noises.

In transmission, the backlash is the amount of clearance between gears, and it is crucial to maintain the right amount of backlash to ensure smooth and efficient operation.

An incorrect backlash can cause the gears to rub against each other, resulting in unusual sounds.

Solution: Adjust the Backlash to the Correct Specification

To fix the incorrect backlash in a tractor, you will need to adjust the backlash to the correct specification. This can typically be done by adjusting the shims or spacers between the gears. 

Problem 2: Hard Gear Shifting

The gear throttle may sometimes not move properly, or you may have difficulty shifting gears. Different factors work behind this problem. Here we’ll discuss that.

Reason: Low Level of Gear Oil

Low level of gear oil makes the gear shifting hard. Gear fluid is responsible for smooth gear shifting. But if the gear fluid level is low, it makes friction between the gear throttle. And for this reason, gear shifting becomes hard.

Solution: Refill Gear Fluid

To refill gear oil, you will need to follow these steps:

  • Locate the gear oil filler hole, usually near the gearbox’s bottom or side. And using a wrench, remove the filler plug or cap.
  • Taking care not to spill any gear oil, slowly pour oil into the hole. You should reattach the filler plug or cap once the oil reaches the full line on the dipstick.
  • Remove any excess oil from the gearbox using a clean cloth.

It’s important to use the right gear oil for your John Deere 5603. It’s recommended to check the oil level periodically to ensure that it stays at the correct level.

John Deere 5603 Hydraulic Problems

Problem  Reason Solution
Low hydraulic fluid pressure  Insufficient hydraulic fluid Fill hydraulic fluid.

Problem: Low Hydraulic Pressure

A hydraulic motor or cylinder will stall if the maximum pressure is too low when moving the heaviest, normal load.

Reason: Insufficient Hydraulic Fluid

In most cases, low hydraulic pressure is caused by low hydraulic fluid levels. When the hydraulic fluid level is too low, it can’t reach your tractor’s essential parts. In turn, this can lead to damage to other important parts.

However, this issue has a very simple fix. So, let’s see what the solution for this issue is. 

Solution: Fill Hydraulic Fluid

You have to go through some simple steps to fill the hydraulic fluid in your John Deere 5603 tractor. Here are those steps. 

  • Locate the hydraulic filter which is available between the pump and the fuel tank. 
  • Next, you just need to remove the filter and fill the fluid. Use a dipstick to prevent overflow. Check the level by using the dipstick. Don’t fill more than the neck level of the dipstick. 
  • After filling in the fuel, lock the filter as it is. 

For further assistance, you may take the help of the user manual of John Deere 5603. 

John Deere 5603 Electrical Problem

Problems  Reason Solution 
Slow starter speed Low battery charge  Recharge battery.

Problem: Slow Starter Speed 

We discovered that the John Deere 5603 has a slow starter speed. There are different reasons why these problems can occur. 

Reason: Low Battery Charge

Slow starter speed can be caused by a low battery charge. To start the engine, the battery is necessary. However, low-charge batteries can’t provide enough power to start the engine at an optimum speed. 

Solution: Recharge the Battery

By using a 12-volt trickle charger, you can charge your John Deere 5603 battery. Follow these steps to charge the battery by using a trickle charger.

You need these tools to charge your John Deere 5603 battery. 

  • A 12-volt trickle charger 

Step 1: First, locate the battery trunk and open it. 

Step 2: Now, connect the charger by maintaining the positive and negative terminals. And input the charger socket into an electrical terminal. 

Step 3: Charging the battery can take 30 to 60 minutes. Start your engine after charging the battery. If you still have a slow starter speed, you may need to replace the battery. 

However, if you face any difficulty in performing these steps, then you may need to contact a professional automobile expert for assistance. 


How Do You Bleed A John Deere Fuel System?

To bleed a John Deere fuel system, fill the fuel tank with diesel fuel and open the fuel shutoff valve. Prime the fuel pump manually with the primer. Upon filling the sight bow on the side of the fuel filter, you can hear fuel flowing back into the tank. Let the engine idle smoothly for a few minutes.

How Much Horsepower Does A JD 5603 Have?

John Deere has 99 engine gross horsepower. Besides that, it has 84 PTO horsepower, according to the manufacturer’s claim, while it is tested at 82 PTO horsepower. However, its engine is capable of producing 65 kW power; that’s enough for mid-level mowing.

What Size Tractor Can Lift 2000 Lbs?

Compact tractors with 40 to 60 horsepower can lift up to 2000 pounds. It is common for tractors of this size to weigh more than 4000 pounds with the loader attached. You may need to adjust this limit if you are driving in rough conditions. 


The focus of this article was on John Deere 5603 problems. Hopefully, this will be enough to know for you.

However, if you find any exceptions, it’s better to contact a professional automobile expert for on-site assistance.

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