6 Common Problems with John Deere 6400 and How to Fix Them?

John Deere 6400 is a powerful tractor that produces a mammoth 100 horsepower, thus making it one of the most popular tractors out there from John Deere. However, even after being such a quality full tractor, it is quite common to suffer from John Deere 6400 problems.

Even though John Deere tractors are reliable,  they can face some problems, and the most typical issues with John Deere 6400 tractors include a diesel engine not starting, a loose steering wheel, broken gear, and other issues.

So, whether you already own a 6400 tractor or thinking of buying one, this guide is for you as today we will discuss all typical problems that you can face with a John Deere 6400 and the probable solutions for them.

Quick Table for John Deere 6400 Problems, Reasons, Symptoms, and Solutions

Below, we will look into six typical problems that you can expect your 6400 tractors to face.

SerialProblemsSymptomsShort Solution
1Auto Quad transmission fail● Tractor won’t move smoothly.● Rebuilding the quad transmission
2Failed Water Pump● Tractor will overheat● Replace the water pump
3Damaged Brakes● Brakes won’t work● Replace the discs
● Clean the suction in the rear disc
4Engine won’t start● No power or sound in engine● Replace Battery
● Refill coolant
● Clean fuel filter
● Clean radiator fin  
5Failed Gear● Weird noises from front axle● Replace gear
6Tight or loose steering wheel● Steering wheel will feel strange in hand● Repair steering cylinder
● Replace steering pump

6 Common Problems with John Deere 6400 and Their Solutions:

So far, we have looked into all possible john deere 6400 problems. Now we will look into each of these problems in full detail and find out how to fix them.

1. Auto Quad transmission fails

Deere 6400 Auto Quad wears down and occasionally fails, which is a pretty frequent problem with regularly used tractors.


There is one single and straightforward reason for auto quad transmission clutch failure, which is

  • if you’re using your tractor to accomplish a lot of heavy lifting, then the quad transmission can wear down


Understanding clutch failure isn’t an easy problem to understand. However, usually, when the quad transmission fails, your tractor will show symptoms like

  • Tractor won’t move smoothly
  • Tractor will cause trouble while reversing


Before you begin the repair, you must first shut down the transmission so that you can reach the pack.

  • You can rebuild the quad transmission.
  • Consult a mechanic in case you can’t rebuild the quad transmission

2. Failed Water Pump

Failed water pumps in the John Deere tractor are a regular problem, and it is not that hard to understand.


There is no exact reason for the failure of the water pump, and it can occur naturally. But, a few factors that contribute to this problem include

  • Improper maintenance of the water pump
  • Leakage in the pump


This problem is easy to detect before any harm occurs, and the most reliable method of diagnosing a failing water pump is

  • Tractor will overheat
  • The gauge will become red, making the overheating warning buzzer active


There is only one solution for a failed water pump, and that is

  • Buy and replace the old water pump with a new one

3. Damaged Brakes

John Deere tractor components are intended to last and to be driven safely. As a result, the brakes might survive for several years. Heavy users, on the other hand, might easily ruin the brakes.


Damaged brakes are a prevalent issue in any tractor and also in trucks and other vehicles. The most common cause of it is

  • With time, the disc gets worn out and slowly becomes damaged
  • Dirt particles might enter the rear disc housing’s suction screen.


Discs are a bit expensive, and you should properly maintain them to ensure that they don’t get worn out easily. However, if they do get worn out, then you will need to

  • Purchase and replace the old discus with new ones.
  • Clean the rear disc suction screen if dirt gets in

4. Engine won’t start

This is the most prevalent issue we heard about all tractors, not just the John Deere 6400.


This problem is caused by a variety of factors, ranging from primary difficulties like empty fuel tanks to more severe issues like clogged fuel injection pumps. The problems are as follows.

  • Dead or damaged battery
  • Lack of coolant
  • Dirty and Clogged fuel filter
  • Dirty radiator fin
  • Dirty disease fuel


Even though there can be many reasons for the engine not starting, the symptom is just one.

  • The Engine won’t power up or make any sound


There can be 5 different reasons for the engine not starting, as we discussed before. So each of these problems has its own solution. Hence, before solving a problem, make sure you know the right reason for it.

  • Charge or replace the battery if it is damaged
  • If your coolant level falls below a certain level, just top it up or replace it entirely.
  • Clean fuel filter fully.
  • Clean the radiator by using an air compressor to blast the dirt away
  • You will have to replenish tainted fuel. Simply fill your tank if you have an empty tank.

5. Failed Gear

Failed gears are not a very common problem for John Deere tractors. But, in case your tractor is suffering from failed gear, read below to know more.


We think you already know the reason for failed gear, and the only culprit is the gear itself.

  • Gear can often get worn out as time passes by


Try starting your tractor and keep running it for a few minutes, and you will notice that.

  • Weird noises coming out from the front axle


When the gear fails, you need to open up your axles and get to the old gears.

  • Replace the old gears with a new one

6. Tight or loose steering wheel

There are two main issues with the Deere 6400 tractor. Those are the steering wheel that rotates very readily and the steering wheel that works extremely tightly.


Many reasons can cause this problem, those include

  • Low hydraulic oil level
  • Steering cylinder problem
  • Used up steering pump


If you have driven a tractor before, then you know how the steering wheel of the tractor feels, and hence detecting this problem won’t be an issue for you.

  • The steering wheel will feel weird in hand


Let’s look into solutions for all reasons one by one

  • When there is low hydraulic fuel, fill up the oil according to the required level
  • Repair the steering cylinder in case of a damaged steering cylinder
  • Replace the damaged steering pump


John Deere is a very famous brand for tractors; however, it tends to suffer from some problems. So far, we have discussed all the common problems and solutions. Now we will look into FAQs related to Deere 6400.

How long does a John Deere 6400 run?

The John Deere 6400 engine typically lasts 6,000 to 8,000 engine hours before requiring additional unplanned maintenance. If properly maintained, the engine may last up to 10,000 engine hours.

How wide is a John Deere 6400?

John Deere 6400 has a wheelbase of 94.5 inches with a length of 165.7 inches and a cab height of 105.9 inches.

Where can I find the serial number on a John Deere 6400?

You will find the serial number tag is located on the right side of the Deere 6400 tractor chassis, next to the front axle.


No tractor is perfect, and every model is prone to some problems, and the same applies to John Deere 6400. Luckily the most typical problems with this tractor are simple to resolve, and you won’t need the help of any professional if you know the root of the problem.

Hence, today we talked about John Deere 6400 problems and their solutions. Whether you are thinking of getting a new John Deere or you already own one. This guide will help you find out all the problems and fix them quickly yourself in no time.

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