John Deere 4320: The Super 4020

John Deere 4320 listings on Tractor Zoom

So if you listen to my buddy Alex (the “4320 guy” in one of my circles of friends), the John Deere 4320 is “hands down the pinnacle of all of the New Generation tractors.” There’s no disputing it, he lays it down as cold hard fact. Fair warning; if you ask him why, you’d best have a chair handy, because he’ll have a lot to say.

And frankly, after listening to him over lunch one day, I’ve got to admit, he’s got a point.

Lots of people talk about the 4320 as a gap-filler, and that’s true – it was. At the end of the day, though, I feel like it was a lot more than that. Let’s talk about why.

Farmers needed options…

The 4020 was (and still is) a fantastic tractor—reliable, versatile, and beloved by farmers. But at just 95 horsepower, it had its limits. In the late 1960s, Deere’s upgrade options weren’t exactly ideal, either. Farmers looking for more power had to make a tough choice: stick with the 4020 or jump to the 141 horsepower 5020, a bigger and heavier machine that simply wasn’t suited for row crop farming. There was a clear need for something in between, a tractor that balanced power and practicality. And for many farmers, that need was becoming urgent.

Missed it by that much….

John Deere listened to the voice of the farmer, and in 1969, they responded with the 4520. Packing 132 horsepower from a turbocharged 404, it was a definite step in the right direction. But while it had the power, it was still based on the 5020, so it still had that 5020 feel. To make matters worse, early models struggled with airflow issues, leading to performance headaches that only added to the frustration. It was progress, but it still missed the mark.

Back to the drawing board…

It wouldn’t be fair to call the 4520 a failure, because it wasn’t. However, Deere knew they’d missed the mark. The right tractor needed strength, yes, but it also needed agility and efficiency in the field. Armed with a better understanding, Deere engineers scrapped their previous approach and started fresh, this time basing their design on the proven 4020 chassis. And when the 1971 model year arrived, they didn’t just have a fix; they had a tractor that checked all the boxes.

Some of you are probably thinking, “Whatever, Interesting Iron-guy, the 4320 was just a 4020 with a turbo slapped on it.” And honestly? That’s exactly the direction John Deere could have taken. The 4020 was built well enough that it probably could’ve handled the extra horsepower without too much fuss. I mean, let’s be honest, how many 4020s are still out there today, running with turned-up pumps and an M&W stuffed under the hood? Plenty. But that’s not how Deere played it. They went deeper than just bolting on more power; they added refinement as well.

Where’s the beef?

The age-old adage in the tractor pulling world is that power tends to find weakness, and that’s 100% true. Without beefing things up, you may have the power but you’ll never be able to take advantage of it. The same thing goes with farm tractors, and Deere’s engineers understood that.

They started by lengthening the wheelbase just a little, from 151 to 159 inches. The overall length also increased by about the same. Yes, it was longer, but it was 10 inches shorter than the 4520, so they were able to retain the agility. However, the frame rails were beefed up a little as well as the driveline. More weight helped with stability and traction.

Engine

The 4320 used the same basic turbocharged 404, but with a few twists. Engineers relocated the injection pump so it could run directly off the cam gear, which was more efficient than the 4020’s setup. They also changed the injectors as well as incorporated a bigger fuel tank (44 gallons for the 4320, 34 for the 4020).

Turbocharged engines make more heat, and Deere made a few changes to handle that as well. The oiling system was completely reworked to include oil jets to cool the pistons and 25% more oil in the system overall (some of that fed the turbo to keep it cool, too). The cooling system was redesigned using an improved pump design, a bigger radiator (which forced a slightly wider hood), and 17% more capacity overall. Finally, the John Deere 4320 used a bigger fan and a (theoretically) better air cleaner system. In practice, the air cleaner system didn’t work all that great, as it was really prone to plugging up, but the fan worked great!

Driveline

On the driveline side, the clutch is a bit heavier, and I believe the gears in the transmission are a bit beefier as well. The 4320 only came with one transmission option; the 8-speed Syncro.

Overall, if there’s only one word you ever associate with the John Deere 4320 (especially when compared to the 4020), it should be “beefy.” Was it overbuilt? I wouldn’t say so, but I think it was a very well-engineered machine.

How’d it sell?

Overall, I’d say fairly well. All tolled, Waterloo produced 21,485 of the John Deere 4320. However, I don’t the numbers don’t really tell the whole story here.

When the wheels were set in motion for the 4320, the 30-Series development was already well-underway. The 4430, which would be the 4320’s replacement, was just a few short years away from its release for the 1973 model year. Quite frankly, the 4320 was never intended to be in production for a long time. In that respect, it really was a gap-filler. Deere knew they had something better in the works, and they didn’t need the 4320 to have a long shelf life.

What’s a 4320 worth these days?

I did a little digging in our Tractor Zoom Pro database the other day, and as you’d expect, values are all over the board. A nice original 2WD (or a top-tier restored example) will sell for $25K or better without much trouble. More average examples will set you back somewhere in the neighborhood of $13K depending on condition. If you stumble on a factory-equipped FWA model in good shape, expect to pay somewhere near $20-25K.

Overall, our data shows that the market has slipped a little bit over the past three years. I suppose that’s to be expected, as the collector market starts shifting towards the SoundGard tractors.

Still, if you find a nice one, they’re a heck of a nice tractor to have in the collection or to put back to work. Sure, there’s some stuff they won’t do, but on the whole I feel like there’s still a place on a farm for these tractors!

Wrapping up…

I’ve always maintained that when it comes to brand, I’m fairly agnostic. I firmly believe that most tractor companies had good ones as well as bad ones, and there are a handful of great ones sprinkled in the mix too. The 4320 may not have been quite as ground-breaking as the 4020, which I believe was probably the most game-changing tractor to roll out of Waterloo in the sixties and early seventies.

At the end of the day though, for a lot of farmers, the 4320 turned out to be just right. At 116 horsepower, but with similar size to a 4020, it bridged the gap pretty darn well. And for that, it deserves a spot on the list of greats.

Anyway, I’ve rattled on far longer than I intended to about the 4320. Must’ve spent too much time listening to my 4320 guy!

Go do something with one of your tractors today, or drag an old one out of the weeds and get it running again; you’ll be glad you did!

And if you’re looking for a 4320 of your own, take a look at a few of these that are up for grabs right now!

John Deere 4320 listings on Tractor Zoom