Which 4000 series to get?

[sweetjeep]

Hey folks.. I am looking at a 4000 series Deere.

Fact is, ANY of them are going to do me fine, but I'd like to get the biggest I can afford.

My particular curiosity is:

The engine in all of them, which I ASSUME is a Yanmar, appears to be the same. According to the advertising, they are all 148 cu motors. And aside from the HP/TQ ratings every rig in the 4000 series is the same (MORE OR LESS!). But the base price is about $5K different.

What is the difference among them? According to the advertising, nothing other than price.

What's to stop me (aside from Warranty concerns) from turning up the motor in the 4120 to the same HP as the 4720? I assume it's little more than turbo settings and fuel pressure.

Does anyone know what the differences are?


Thanks alot!

 

[RoyJackson]

The 4xxx series engines are built by Deere in the US.
I expect you're correct in it being a matter of turbo and injection changes. It may be pressures or a combination of pressures, injectors and other components.

First, I am sure any modifications would void your warranty...think about that before you make any changes.
Then, you'll want to get the work shop manual for this series tractor before you consider any modifications.

I'd say you've got a couple years to think about what you want to do...

 

[wolc123]

Like Roy says, No Yanmars in these. This is the only series of JD compacts equipped with JD powertech engines. They are quite large, really more of a utility than a compact. Note that the hydraulic capacities is equal for all, only spec difference is hp and cost. Tinkering with the engines to increase hp will likely void the warranty and because this is a relatively new model, most are still covered. Don't be suprised to find that someone figures out how make a 4120 into a 4720 or better in a couple more years, and I am sure we will all read about it right here. I heard that JD uses this same engine at even higher hp in some skidsteers.

 

[sweetjeep]

Hmm.. thanks guys. I am quite sure that's the case. I find it FAR to concidental. Plus it makes sense.

If I do end up getting one, which is moderately likely, I'll try my best to ferret out the details. The main problem is there are still so incredibly few "tractor folk" online and details are so god awful sketchy.

I might be able to get part numbers of turbos and injectors and the like. But.. then again, it could be like a lot of the old IDI diesel motors, there is a screw on the fuel pump, in for more power, out for less.

Maybe..

I'm not terribly concerned about the warranty, "prove it". But I am also very UNconfident I'll be able to find a used one.

 

[RoyJackson]

The most important thing is to get the service manual. That should give you all the information you need.
If it's just a screw setting (which I doubt), it'll probably be sealed in some way...but you can figure that out when the time comes.
ANother thing...when the time comes, get cozy with a service tech...he probably won't do the work...might point you in the right direction though.

 

[Greyfields]

What's to stop me (aside from Warranty concerns) from turning up the motor in the 4120 to the same HP as the 4720? I assume it's little more than turbo settings and fuel pressure.

This has been discussed a lot on the forums here. AFAIK, no one has quite figured out a way to do so yet. Apparently there are electronics preventing anyone from doing this and I'm not sure if someone figures it out they'll be brave enough to post about it. However, someone did manage to adjust their timing forward and gain extra HP.

I am running a 4120. If I did it all over again, I'd maybe lean towards the 4320. There is an abundance of implements out there for 40 HP PTO's, but then things get a little scant once you're down to 35 HP PTO on the 4120 like me. Remember that the 4120 is identical to the 4720 in every way except the horsepower.

But, am I getting by well with my tractor. It's small enough to get into the garden area. I leave on horendously wet soils, and I still drive it all over the lawn. On R4's, the tracks go away in a couple days if the grass is growing. People on here would swear that a 3700 pound tractor kills grass just by looking at it. I'm not finding that to be the case.

When my next shipment arrives from the tractor store, I'll even be baling with a CUT without issue. So, the 4x20 series are fantastic tractors in my estimation. I am running (i.e. driving around in circles iwth a grin on my face) a 6' brush hog, 6' disc mower, 6' tiller, PHD, 6' offset discs, 2 bottom plow, rake/tedder, 7' seed drill and a baler! Could life get much better?

 

[gamble77]

4520 & 4720 = larger turbo

 

[sweetjeep]

I had a local sales guy do some digging for me and all he could find was what gamble77 just said: Larger turbo. The sales guy couldn't come up with any other differences.

I'm generally happy taking on tasks I have no business with, but swapping out a turbo, not rocket science.

Only a lb or 2 in boost can make a pretty large difference in HP/TQ. Being a fixed vane turbo makes it fairly cheap. Certinally less than the $1500 sticker price in the tractors. 4120 -> 4320.

With a fixed vane there shouldn't be any electronics controlling anything, only fuel flow. Again, I'd be stunned if the fuel pump wasn't adjustable.

Either way, I'm not a farmer or anything. So a lack of implements for a sub 40hp tractor is not an issue. For that matter I could just lug a larger implement and drive slower or just be more careful. I am just looking to build a house and need to upgrade but I'm looking to do it as cost effectively as I can. And if I have another reason to tinker with something, all the better!

 

[Greyfields]

The turbos are actually identical, just set to a different boost. But, they knew people would recognize this and have it set so that if you fiddle with your boost, your tractor won't run. That's in layman's terms. It's been explained several times on here by people who know more than me that the engine is coded a certain way and will not run without the turbo matching what it wants it to be. Good luck with the modifications and I'd be the first person to pump up my 4120.... I just think they expected this and it won't happen.

 

[CWP37]

If you can afford it, I'd always say get the most hp available in a given series.

I also looked at buying a 4120 and tuning it up. I talked to a diesel mechanic who used to run a Deere dealership. He said that the 4x20s are electronically controlled and that the only way to kick up the hp is to reprogram. Supposedly, Deere has it set up so that can't happen.