If you will be putting your tractor on a trailer, using it on your lawn, or have tight spaces, the 3720 is probably the better choice. Otherwise, the 4120 wins hands down. JD powertech engine and look at the difference in hydraulic capacity, not even close.
3520 vs 3720
- Thread starter NYBOB
- Start date
- Views: 11136
I feel it is insane how many thousands John Deere wants for that turbo and injectors on the 3520 and 3720 over the 3320. Where I live, John Deere dealers stock nothing but the 3320 because that is the only thing that sells. People don't want to get ripped off for that few extra hp that you usually can't tell the difference with anyhow.
The only possible real advantage I can see with the larger hp tractor would be heavy PTO work, probably in the form of a cutter. There would be absolutely no advantage with a log splitter because the hydraulic pumps are identical on all the 3xxx series. As a matter of fact, everything is identical on all the 3xxx series but the engine except the 3720 does a little larger radiator.
The only possible real advantage I can see with the larger hp tractor would be heavy PTO work, probably in the form of a cutter. There would be absolutely no advantage with a log splitter because the hydraulic pumps are identical on all the 3xxx series. As a matter of fact, everything is identical on all the 3xxx series but the engine except the 3720 does a little larger radiator.
Kyle_in_Tex
Super Star Member
The 3720 includes an intercooler. The power is noticeable. It is hard to explain but a turbo adds the perfect kind of power that a bush hog needs...TORQUE!!! When a 3320 bogs down in deep grass with a 5' cutter, a 3720 will power on through.
Yes it does add $$$ to the price but you are getting a world class Yanmar diesel which are 2nd to none. Add a turbo and intercooler to any car and it will cost thousands more.
Yes it does add $$$ to the price but you are getting a world class Yanmar diesel which are 2nd to none. Add a turbo and intercooler to any car and it will cost thousands more.
GreenMtns
Gold Member
Regardless of your choice, 3520 or 3720, you need to be aware that the small turbo turns between 45000 and 60000 RPM's according to my tech guy. He went to JD class and that was one of the things they were shown. The bigger tractors turbos turn slower. Always idle the engine for a few minutes after working the engine hard. The temps in the turbo are very high and when you turn off the engine the oil flow stops. The oil in the turbo turns to carbon almost instantly if not cooled down before shut off.
As to which is the better model, only you can decide. Here I use a 3520 cab model which runs a 6' rear finish mower, 6' Rotary mower, 34" Tiller, 34" Snowblower, Jinma 6 chipper, Pulls a 2 bottom Ferguson plow and 6' Dearborn disk harrows and does it all effortlessly. I will state however that my land, while not flat, is not very hilly either.
I don't think you will go wrong with either of these models. They are both great machines. The intercooler on the 3720 will only come into play if you use the tractor really hard and get the Oil temp's up in the very high range.
Al
As to which is the better model, only you can decide. Here I use a 3520 cab model which runs a 6' rear finish mower, 6' Rotary mower, 34" Tiller, 34" Snowblower, Jinma 6 chipper, Pulls a 2 bottom Ferguson plow and 6' Dearborn disk harrows and does it all effortlessly. I will state however that my land, while not flat, is not very hilly either.
I don't think you will go wrong with either of these models. They are both great machines. The intercooler on the 3720 will only come into play if you use the tractor really hard and get the Oil temp's up in the very high range.
Al
jcmseven
Veteran Member
I know there are many happy 3320 owners out there, and they are fantastic machines. I have had both, a 3720 (two actually) and a 4310, which is the predecessor to the 3320 (I think it was rated at 58 lb. ft. of torque v. the 3320 at 62). I can say without ANY doubt, although the 4310 was a really nice machine, the 3720 is the much more powerful choice. I feel fairly confident this fact carries over to the 3320. In Kahuna's area the 3320 is a popular machine, and I am sure they sell well. In my area, 3320 and 3120 machines sell poorly v. the turbo models. I am not saying they do not sell, just at a slower rate. I really believe the mid frame machines are the best compacts for most of us that JD sells. Having had a large frame, which I really loved for many reasons, I would have to say it offered nothing objective in what I wanted to do over the 3720 I currently have. I have fallen for the "buy bigger" (physical size) trap myself, and although I loved my 4520, I would say for practical reasons it was too much for me. I really think our original poster is saying he wants a mid frame, and he is debating about whether to fork over the extra dough for the extra power. Yes, it is expensive, but obviously JD knows something, as many of us fork out extra for the turbo engines. Is is worth it?? I think so, as for me at least the frustration of my 4310 laboring to the top of my drive and bogging pulling a box blade's worth of gravel was reason enough to upgrade in power. In this way, and in others, the difference is a lot. Keep in mind we are looking at over 20 ft. lb of torque in the same size package and 12 horsepower. That is a pretty large difference (between a 3320 and a 3720). Of course the 3520 is closer, but is quite close in price to the 3720, so why at that point not go full bore???
John M
John M
browns40
Gold Member
Hi All,
I've owned a 3320, and now a 3520--some would argue it was not enough difference to warrant the trade, but fear of my 3320's mysterious ability to shred wheel & rear main seals were the real motivator more than power...
What I can tell you is the 3520 does have noticeably better performance under demanding PTO conditions--bush hog, tiller, winch, (also snagging the box blade & keeping traction)--the turbo/loadmatch wind up extra torque more quickly than the 3320 could.
For the size of the machines, unless your heart is set on "oversizing" your PTO implements (going a foot+ over JD's recommended width & weight), you will not be able to work beyond a 3520's capabilities (with RPM right & slip clutch functioning properly) and only rarely beyond a 3320's.
Only mobility questions: altitude, huge elevation changes, and bragging rights on the 0-19 tractor time trial would weigh in otherwise for me. I am not travelling on mine, and I'm not bouncing along too fast during any kind of work...
I would put that extra dough towards a couple implements you were looking at, and have no regrets.
I've owned a 3320, and now a 3520--some would argue it was not enough difference to warrant the trade, but fear of my 3320's mysterious ability to shred wheel & rear main seals were the real motivator more than power...
What I can tell you is the 3520 does have noticeably better performance under demanding PTO conditions--bush hog, tiller, winch, (also snagging the box blade & keeping traction)--the turbo/loadmatch wind up extra torque more quickly than the 3320 could.
For the size of the machines, unless your heart is set on "oversizing" your PTO implements (going a foot+ over JD's recommended width & weight), you will not be able to work beyond a 3520's capabilities (with RPM right & slip clutch functioning properly) and only rarely beyond a 3320's.
Only mobility questions: altitude, huge elevation changes, and bragging rights on the 0-19 tractor time trial would weigh in otherwise for me. I am not travelling on mine, and I'm not bouncing along too fast during any kind of work...
I would put that extra dough towards a couple implements you were looking at, and have no regrets.
orlo
Platinum Member
You guys are making me think again. I'm trading in my 3320 for a 3720 cab (Instead of trading in my 2305) but now you've got me thinking again.... 
Maybe I should keep the 3320 and trade the 2305. I can change my mind until the 3720cab comes in...
For me my 3320 (open) is fine power wise for all I do, but I figure the A/C compressor, bigger alternator, etc. takes a few HP on the cab tractors so I wanted at least a 3520 so I went all the way to a 3720.
Hydraulics take far less than total hp so there is no advantage in any of the 3000 series - They all produce the same pressure (2500psi) and flow. They all produce 12.5 hydraulic HP for implements, and 7.7 (max) for power steering. If you were using the hydraulics while using the mechanical PTO that would be a different story since the accessory would add to that and total HP would become far more important.
Also, I would have loved to go with a 4320 or 4520 cab but they are too high for my garage (95"). Also they don't have a blower available but that could be easily solved with a high volume PTO pump and a skid steer (boom) mount hydraulic blower.
Maybe I should keep the 3320 and trade the 2305. I can change my mind until the 3720cab comes in... For me my 3320 (open) is fine power wise for all I do, but I figure the A/C compressor, bigger alternator, etc. takes a few HP on the cab tractors so I wanted at least a 3520 so I went all the way to a 3720.
Hydraulics take far less than total hp so there is no advantage in any of the 3000 series - They all produce the same pressure (2500psi) and flow. They all produce 12.5 hydraulic HP for implements, and 7.7 (max) for power steering. If you were using the hydraulics while using the mechanical PTO that would be a different story since the accessory would add to that and total HP would become far more important.
Also, I would have loved to go with a 4320 or 4520 cab but they are too high for my garage (95"). Also they don't have a blower available but that could be easily solved with a high volume PTO pump and a skid steer (boom) mount hydraulic blower.
