John Deere 4840 Problems (Let’s Find the Best Solutions)

John Deere 4840 tractor is not uncommon in the market. But no vehicle is free from problems. Apart from its amazing performance, you might be concerned about the problems.

Some of the common John Deere 4840 problems are noise from the engine, the engine not starting, noise from the transmission, and the 3-point hitch rising slowly. These problems may occur for various reasons, like clogged fuel pipes, damaged bearings, cold hydraulic fluid, etc.

So if you are interested in knowing the reasons behind such problems and the solution, then bear with us.

Common Problems of John Deere 4840
Source: Discuss.machinerypete

John Deere 4840 Engine Problems: Solved

Problem Reasons Symptom Solution
Engine fails to start or is difficult to start Fuel filter is blocked with something.

Clogged fuel valve

Faulty fuel injector

Damaged cylinder compression.

While starting the vehicle, it won’t start easily or might not start at all. Clear the fuel filter if needed.

Open the supply valve for fuel injecting.

Test the fuel injector. Replace it if necessary.

Reduced power in an engine Damaged Injector

Jammed oil filter

Jammed air filter

Overloaded engine

Incorrect idle setting

The power warning indicator will show reduced fuel or air in the engine. Replace the fuel injector.

Clean the oil filter. If is damaged, change it.

Clean the air filter. If damaged, then change it.

Noise coming from the engine Low oil level in the fuel tank.

Dirty or damaged fuel injection nozzle

Broken piston rings

Loose flywheel mounting spring

Unusual noise coming from the engine while running or starting it. Fill the fuel tank with the required oil.

Change the injector nozzle if required.

Replace the piston rings.

Problem 1: Engine Not Starting or Hardly Starting

John Deere 4840 Engine Problems
Source: Bootheeltractorparts

One of the utmost common issues one might face with the John Deere 4840 is the engine not starting issue.

You find your engine is stopped all of a sudden, or the engine is starting late or not starting at all. There can be a few reasons for this to happen.

Reason 1:

A fuel filter clogged with dirt and dust is one of the main reasons for this to happen. In the engine, the fuel should have direct access without any obstacles.

If the fuel filter is clogged, that will cause issues like the engine not getting enough fuel. Hence the engine stops.


The best solution to this issue is to clean the fuel filter. That way, the oil access would be difficulty-free. However, replacing the filter is better if the condition is not very good.

Reason 2:

Clogged fuel valve is another problem that creates obstacles for arbitrary fuel flow. The very first thing that an engine requires is fuel. If that flow gets disturbed, the whole system will be affected. So the engine doesn’t start.


Here, you have to check if the valve is clogged and if it is in the state of cleaning. If the valve is not at its best after cleaning, you might need to change the fuel valve.

Reason 3:

Fuel injector clogged or dirty can be a reason for engine noise. Again it creates obstacles for the engine to get the required amount of fuel. Thus the engine is stopping or not starting to warn you something is not right.


It’s best to replace the fuel injector if they are clogged. Although sometimes by testing and cleaning work. But it is always best to get a new injector to avoid such problems anytime soon.

Reason 4:

If your vehicle’s cylinder compressor goes wrong, the engine might make unwanted noise. Since the compressor is a combination of different components, you have to check carefully exactly which parts went wrong.


you have to check the cylinder compressor carefully to figure out which component is damaged. As soon as you find the component, replace it with a new one and check if the engine is working properly or not.

Other than all these mentioned problems, sometimes air in the fuel system or injection pump failure can also be the reason for stopping the engine. However, these are not serious problems.

Problem 2: Less Engine Power

Less power in the engine shows that the engine’s fuel or air level is down. Through the indicator. This can happen at any point in time while driving. Sometimes this can be a matter of trouble for the user.

Reason 1:

If the injector is clogged with dirt and dust or damaged by any means, it can show problems like reduced power supply to the engine. This is quite a familiar issue for this particular problem.


In such issues, it is better to change the injector than clean it. Once such issues arise, it doesn’t help much until you change the injector.

Reason 2:

Jammed oil or air filter is a common issue for John Deere tractors. Since tractors are mostly used for farming, it is quite common for vehicles to get clogged filters. However, this problem is easily solvable.


Such problems can be solved by both cleaning or replacing the filters. In most cases, cleaning doesn’t help much. Although, if you have a new tractor, you can go for cleaning. Otherwise, it is good to replace the filter.

Reason 3:

Sometimes, if you overload the engine, this problem may arise. Every vehicle has its own capacity. You shouldn’t exceed the load. Otherwise, it will show reduced power in the engine.


you need to reduce the load immediately if you have overloaded the engine. Sometimes it leads to other damage to your vehicle.

In some cases, incorrect idle settings, dirty hoses, or compression loss in the engine can also cause the same issue. Regular maintenance would help to get rid of such issues.

Problem 3: Unusual Noise from Engine

It is a very common problem that one might face with their John Deere tractor, whose engine makes noise. If you find your engine is making noise which is not usual, then this should be examined carefully and immediately.

Reason 1:

If the fuel tank’s fuel level is not up to the mark, such a problem can occur anytime. The engine needs enough fuel to run properly. If the fuel is any less, it will make noise.


You need to check the fuel level and determine if it is enough for the requirement. If the oil is less, fill it to the necessary amount. This is an easy solution, and you can easily resolve it.

Reason 2:

in some cases, your fuel injection nozzles can go bad or dirty. If you use your vehicle regularly, such a problem is normal. If you check your vehicle regularly, you can find the problem easily.


You must replace the injection nozzle if you figure out such issues. Sometimes you also have to change the nozzle and place the new one. That way, you can be tension free for many days.

Reason 3:

Worn out crankshaft or the main bearing can be the main reason behind the engine’s noise. While using the tractor for heavy work regularly, such issues may take place. However, this is not a serious problem.


To eliminate the issue, immediately replace the bearing and the crankshaft. If you have basic expertise in vehicles, you can easily make replacements. Otherwise, ask for the expert’s help regarding this.

Reason 4:

If your vehicle’s piston ring is damaged or broken, it might cause noise in the engine. Piston ring damage is nothing new for a vehicle. But the issue needs to be resolved immediately.


since you cannot repair the piston rings, you must replace them. This can be done by you, or else you may consult someone expert to change the piston rings.

John Deere 4840 3-point Hitch Problem: Solved

Problem Reasons Symptom Solution
3-point hitch rising slowly Cold hydraulic fluid.

Defective hydraulic pump.

Blocked hydraulic oil filter.

Faulty hydraulic cylinder.

While having such an issue, you will find low fluid or a clogged hydraulic filter.

You may also find low hydraulic fluid in your system.

Warm the hydraulic fluid to the required level.

The hydraulic filter should be replaced.

The hydraulic cylinder should be replaced or changed if required.

Problem 1: 3-Point Hitch Raise Slowly

The 3-point Hitch issue is not a new problem for tractors. You might face this issue with John Deere 4840.

Most of the time, such issues arise due to hydraulic fluid or hydraulic pump issues. However, you can solve these problems by making a few adjustments.

Reason 1:

If your hydraulic fluid temperature is below what it requires, the 3-point hitch will rise slowly. Maintaining the optimal temperature of the hydraulic fluid is crucial to ensure your vehicle operates properly.


You must warm up the hydraulic fluid to resolve the issue. You can use a screw-plug heater to warm up the fluid.

You have to make sure the size and the weight match your vehicle. You can have a silicon rubber heater outside of the fuel tank to preserve the heat of the fuel.

Reason 2:

Blocked hydraulic fuel filter is one of the common reasons for the 3-point hitch slow rising. You must keep your hydraulic fuel filter clean and damage-free. Otherwise, facing a 3-point hitch issue is obvious.


Hydraulic fuel filter maintenance should be a regular job for any tractor user. You must clean the fuel filter in a few months to avoid clogged fuel filters. If your filter is badly damaged, you must replace it immediately.

Reason 3:

Defective hydraulic cylinder can be another reason for the slow rising of the 3-point hitch.  There can be damage to the wiring or the components of the cylinder.

Inspecting each component properly is important to figure out where the problem lies.


First, check the hydraulic cylinder section properly and figure out the root of the problem. It can be damaged, worn, or any kind of defect on the cylinder itself.

In most cases, you need to replace the damaged components to make them work properly.

John Deere 4840 Transmission Problem: Solved

Problem Reasons Symptom Solution
Noise coming from transmission Worn or damaged bearing

Incorrect backlash

Dirty transmission fluid.

You will hear gurgling noise while shifting gears. Bearings need to be changed.

Make adjustments in the backlash that is needed.

Replace the transmission fluid with a clean one.

Problem 1: Noise from Transmission

John Deere 4840 Noise from Transmission
Source: Salesmanual.deere

Sometimes, you would notice transaxle gears making a whining noise while the tractor is moving, which is not usual.

Mostly any kind of issues related to transom leads to such problems. Also, if the tractor or transmission is brand new, such problems may arise.

Reason 1:

Due to damaged bearings, such problems can arise in the transmission. After a while of using a tractor, bearings can get damaged, or the bearing gets worn out. But those damaged bearings make noise in the transmission.


In such cases, replacing the bearing is better than trying to fix it. Bearing adjustments does not really help here. So if you are having issues with bearings, you need to replace them to resolve this issue.

Reason 2:

Backlash is connected with gears. If the gear is not adjusted properly, it will create certain noise from the transmission. But fixing this problem is very simple.


To adjust the backlash, you can change the gear. That way, in most cases, the problem gets fixed. If it doesn’t work, make adjustments in the backlash.

Reason 3:

Dirty transmission fluid is one of the common problems that further causes most of the transmission problems.

The problem is, most of the time, noise from the transmission. It is very important to keep track of whether the transmission fluid is clean enough or not.


If the transmission fluid is dirty, it must be changed immediately. Refill the fluid tank with fresh fluid and ensure you take care of this issue further.


Is John Deere 4840 a Good Tractor to Go for?

According to Gingell, John Deere 4840 is one of the best tractors available. It has retained the resale value quite well. Along with its best performance, this tractor also has a decent price point.

What is the Horsepower of the John Deere 4840?

The power configuration of John Deere 4840 is, Drawbar 157 hp 117.1 kW (Claimed) and 151.21 hp 112.8 kW (Tested). PTO 180 hp 134.2 kW (Claimed), PTO 180.63 hp 134.7 kW (Tested). Overall under this price point, this can be the best deal.

Is John Deere the Best Tractor to Rely on?

John Deere tractors are considered one of the best tractors available in the market for their configuration and resell value. So you can rely on this tractor easily. Although there are some common issues one might face with it, this is true for all tractors.


We hope you know all the common John Deere 4840 problems by now. We have also provided all the possible solutions there is for those problems.

Most of these issues can be avoided if you take care of your vehicle regularly.

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