John Deere 3720 vs. 4120

[ArtVandelay]

I am trying to decide which size tractor would be better for 9 acres of pasture that I have to mow. I get a lot of tall reed canary grass on the land (if it's not mowed regularly) and that grass can grow up 6 feet tall and 1/2 inch thick. IMO, anything less than 35 PTO hp and a 5ft bush hog would be too weak to do the job in a reasonable amount of time. I am thinking about going with a 5ft bush hog instead of a 6ft because the 5ft would be more powerful at 35 PTO hp.

I will also be tilling about 1/2 an acre, and possibly be removing a few small tree stumps occasionally.

I know some people may say a Kubota B3030 would be fine, but IMO that is ridiculously weak unless I wanna spend 10 hours mowing each time. I am not someone who likes to buy the absolute minimum equipment that I would need. I think that a little too much power is better than not enough power.

I was thinking about the JD 990 too, but I would rather have something a little nicer and more comfortable.

Since the cost difference between the two tractors (3720 vs. 4120) is not very much, is it worth it to get the 4120? Will the 4120 make deeper rutts in the ground, or will it's wider tires prevent that?

Thanks.

 

[Keith_B]

I wouldn't think the weight differences be significant enough to make purchasing the 3720 an advantage. Given the type of heavy duty mowing you plan to do I would move up a to a 4320 or 5205.

 

[Greyfields]

I would go with the 4120 simply because you'll have more hydraulic lifting capacity. Also, the wheelbase on the 4x20 series is right at 6'. Running a 5' mower could be awkward, since you'll have to overlap your last pass more than usual.

I have a lot of reed canary grass here, as well as tussock. I mow at about 3.5 mph when I'm going through tall stuff (with a 6' rotary cutter). Occassionally, the turbo kicks in a bit, but it won't even slow you down.

 

[ArtVandelay]

I think the minimum I could get by with is the JD 3320 with FEL and LX-5 rotary cutter. The ideal setup would be a JD 4120 with FEL and LX-6 rotary cutter.

 

[jcmseven]

Art,

Having had both two 3720's and a 4520 and, sadly, too many other JD's to count at this point, I would say go 4120. I went smaller again because for my locale my 4520 was simply too large to fit some places I needed. For my currently the 3720 is perfect in size. For you though I think you would find the 4000 series machine to be more stable and ride better over rough terrain, such as the type mowing you mention. It has plenty of power as the PowerTech engine has a lot of torque. The 3720 is a hoss, though, and would easily run a large RC or RFM without straining. I have pulled a 7' behind mine before and it did not notice it, even in really deep grass. I suspect the 4120 would be similar. I understand Keith's point, but in my opinion, the upgrade in power from a 4120 to a 4320 is not enough to really do. My neighbor has a 4320 and I have operated a 4120 before, although I have never owned one. I could tell zero difference between them, although I will say I had limited seat time on the 4120 I had. If you are looking for more power than the 4120, I suggest the go-for-broke 4720. It is a monster and would power any cutter over anything at anytime without any problem.

John M

 

[jcmseven]

In my previous post, I did not mean to imply that I "sadly" owned John Deeres, just that I am sad I did not get to keep them all!!!!!

John M

 

[ArtVandelay]

Thanks for the responses everyone.

 

[Kyle_in_Tex]

I think the 3320-3720 would do you fine for most tasks. The 4120 does not take that much more room to turn, if you need to do heavier tasks, it would be more stable and powerful hydraulics. The turbos on either frame will give you MUCH more "grunt"/torque. The 3320 has no turbo.

BTW, does ArtVandelay import or export?

 

[ArtVandelay]

I think the 3320-3720 would do you fine for most tasks. The 4120 does not take that much more room to turn, if you need to do heavier tasks, it would be more stable and powerful hydraulics. The turbos on either frame will give you MUCH more "grunt"/torque. The 3320 has no turbo.

BTW, does ArtVandelay import or export?

ArtVandelay is an importer/exporter

 

[kozak]

Glad to see that your deciding on a more capable machine. Just like you said, anything below 35 PTO HP would be too weak & why risk going too small when you know you have a relatively large task you want to do that won't take you all week.

From a rutts perspective, 2900 lbs versus 3700 lbs makes the 3720 the clear winner. 800 additional pounds in the right circumstances....well.....you will sink deeper. Now from a ground engaging standpoint or doing FEL work & other tasks, more weight is a good thing. So you will have to balance & weigh the trade-offs.

The only advantage I see in the 4120 is a smoother running machine (4 cyl.)& a little more torque & hydraulic lift. For your task this would seem to be the clear winner as you will be riding that tractor for hours at a time.

Both machines have pretty much the same capabilities. From an operator fatigue standpoint I think you would be happier with the 4120 & if the price difference is not that great the 4120 would be an incredible tractor to own & operate.

Keep us posted with whatever you decide.

Good Luck,

Vic