John Deere 4640 Problems: Common Issues and Ways to Deal with Them

The John Deere 4640 is a classic tractor made by the John Deere company in the US between 1978 and 1982. Although the period of manufacturing wasn't that long, the company manage to build thousands of these machines and a lot of them are still alive. Yes, they aren't that up-to-date or technological, but they do their job and don't ask for a lot of attention.

Today, we'll be looking at the main specs, common problems, pros and cons, and also at important features that the John Deere 4640 offers. Of course, we'll also look at this machine with an understanding of its age and the limitations it has now in comparison with any modern tractor. But we feel we should pay attention to this wonderful great-grandfather of modern tractors.

Here's what we'll be talking about:

• John Deere 4640 main specs and features as of today.
• What kinds of work can you do with the John Deere 4640?
• What's the average durability of this tractor?
• What are the common problems of the John Deere 4640?
• Should you buy this tractor now or better choose something more modern?

Let's get started!

What should you know about the John Deere 4640 tractor?

This tractor was just one of the big series of John Deere tractors made in the late 1970s and early 1980s. The machine was close to perfect at the time of making and was praised in nearly all agricultural magazines for its wonderful specs and opportunities to do the job.

According to its design, it was just an average tractor with nothing special. But at the time of manufacturing, it was a really good row-crop tractor that could do a lot of things thanks to different original and aftermarket attachments. The original price was about $50,000 depending on the chosen version.

Here are some of the key features you should know about the tractor:

• it is powered by the 7.6L 6-cylinder diesel engine that was engineered by John Deere company;
• with 155 horsepower and about 530 lb-ft of torque, it was a much more capable tractor than the majority of its counterparts;
• you could buy a 2x4 or a 4x4 option of the tractor, the all-wheel-drive version cost more, of course;
• not so many attachments were developed for this tractor, they indicate that this is solely the row-crop tractor with no other purposes considered;
• the 16-speed transmission seems like a great solution for this workhorse allowing it more flexibility when on the field;
• this iron horse wasn't made for fuel economy, you will have to refill that huge 314-liter fuel tank quite often;
• we should say that the simple hydraulic system is pretty reliable and even now a lot of these tractors don't have problems with it;
• of course, you can buy a lot of aftermarket attachments that are being engineered even now.

This wonderful tractor is quite old. The freshest models are 40 years old in 2022 and this is a lot even for this iron horse. So, a lot of these tractors are dead now. But thousands of them are still able to help farmers when working in fields. And a lot of attachment manufacturers still present some new types of loaders and other agricultural attachments for the John Deere 4640.

If you are considering buying one of these tractors, you should pay attention to the overall condition and engine hours. Unfortunately, it's impossible to have the engine diagnosed with any computer tools because this engine simply doesn't have any computer or ECU in it. On the other hand, it's not that hard to see if the engine is going to die soon.

How long can the John Deere 4640 live?

Actually, these tractors are very tough and can survive even the worst working conditions. Any 4640 is over 40 years now, so if you still can start it and make it move, it's a really good tractor. And yes, we can see plenty of them working in fields and laughing at newer tractors getting stuck after sucking in some dust.

The average tractor's lifespan of 10,000 hours in the US seems a childish thing for the John Deere. It can last over 15,000 hours and even more. With this great John Deere diesel engine, you can expect this tractor to be nearly eternal. Of course, for this, you will have to maintain and repair it once something goes wrong.

If your John Deere 4640 breaks down earlier than 10K hours, we should say there was something wrong with the maintenance. We haven't heard any farmer saying anything bad about these tractors. Actually, a lot of farm owners say this is the best and the longest-lasting tractor they have ever used.

What kinds of work can you do with your John Deere 4640?

This is a row-crop tractor, but it can do whatever you need, just buy or engineer the needed attachment. Of course, these machines will not have as many original John Deere attachments as the newer tractors offer, but you can buy some aftermarket options and there are some good deals, for sure.

You can use the front hydraulics for loading, cleaning, lifting, etc. And the rear part of the tractor is mainly used for agricultural purposes when working in fields. The more attachments and extensions you have in your possession, the more types of work you'll be able to do with the John Deere 4640.

What are the common problems with the John Deere 4640?

This model of the tractor is perfect for many kinds of work but it still comes with its own set of problems. And some of them are inevitable even if your tractor has been stored carefully in the hangar for 40 years without being started even once.

Here are some of the most common problems and possible solutions for them:

1. Age

Yes, the John Deere 4640 is an old tractor. It's not the piece of equipment you would love to buy for your farm if you want a reliable and long-lasting tractor, at least, not in the 2020s. The age brings other problems like poor overall reliability and technical problems that come from aged parts and mechanisms.

Unfortunately, you can't do anything with the age of your tractor. When the John Deere becomes too expensive to maintain, you should think about replacing it with a more modern piece of equipment. Even though new tractors are not as long-lasting as the new John Deere 4640s were in the 1980s, the new machine will work better.

2. Fuel consumption

When the John Deere 4640 was made, no one was caring much about fuel consumption. A tractor could drink diesel fuel like you drink water in the morning after a crazy party. The 6-cylinder diesel engine doesn't care about your budget and about prices for diesel fuel - it will keep digesting as much as possible.

3. Rear axle problems

This problem was common even when the tractor was new and it happens sometimes now. The rear axle may need some extra attention if you overload the tractor. This is the weak point and sometimes owners even installed the whole axle assembly from other tractors to avoid these problems.

4. Cracking fuel tank

Unfortunately, this was a common problem since the 1980s and John Deere made some effort to deal with it. But some tractors will still have this issue. If the fuel tank cracks and leaks, you may lose hundreds of liters of diesel fuel and also contaminate your field or farm yard. To predict or prevent this issue, you should just look at the tank regularly and make sure there are no small cracks on it.

5. Grinding when shifting

The transmission is pretty old and it wasn't very technological even 40 years ago. After putting on some thousand hours, these transmissions always start griding when you shift gears. It's not a really big problem and it doesn't mean the tranny needs repair or maintenance. This problem will just annoy you all the time.

6. Head gasket problems

If you see leaks on your engine in the John Deere 4640, the best solution is to stop the engine and investigate the problem. In most cases, the reason for these leaks is the blown head gasket. The big engine works under high pressure and the gasket just has a hard time trying to survive. This happens especially often with tractors that are maintained with cheap aftermarket parts. But even original John Deere gaskets may leak quite often.

The main problem is that you will have to disassemble the head to repair this issue. The gasket is relatively cheap but the labor will cost you some money.

Final words

Even though we like the John Deere 4640 and think this was one of the best tractors Deere made in their history, we wouldn't recommend buying one of these. They all have many years behind and this may create additional problems for you. Also, these tractors are not very economical which may be a problem for any farmer. But if you already own one, you may keep on using it for many years to go.