Comparison JD 3720 vs 4720

jloven · Feb 18, 2015

I Have had a 3 series tractor for about 10 years now, first a 3320 and later trading up to a 3720. I really like the 3720 but lately have really been thinking about getting into a bigger frame. I do a lot of hillside mowing and use a PTO wood chipper so the extra HP could be useful. Would also like a higher capacity front end loader with more reach. Can anyone give me their impression of the 4x20 tractor compared to the 3x20 series? How much bigger? How difficult will it be to trailer vs 3x20 series? Can you add a mid mount drive over mowing deck to 4x20 tractor? I have one for the 3720. Will my 448 backhoe work with 4720 and can I use the same mounting hardware and power beyond kit? Thanks for the feedback

jenkinsph · Feb 18, 2015

Have you done a side by side comparision at the dealer lot? That is where I would start, I did this back in 2009 and decided to go with the 4520 cab. I have heard the rumor that the mmm deck for the 4xxx has been dropped. I would pin down the particulars with the selling dealer about attachments since he is the ones feet you will hold to the fire so to speak.

El Wood · Feb 18, 2015

The MMM is not available on the 4 series tractors.

Did you notice a big difference between the 3320 and 3720 tractors? I have a 3320 but almost got the 3720.

9973720wb19 · Feb 18, 2015

i owned a 3720 for about a three years and traded it for a 4720 about two years ago. i have a few steep hills, and never felt the 3720 was stable. for me the 3720 had plenty of power, but tippy. the 4720 is more stable and is working out fine for me. of course a 5 series (but id have to give up on the HST which i really like) would be even more stable but im not a farmer and that's more tractor than i need. i use my 4720 with a 72" Woods brush mower, 84" Frontier grooming mower, i have the 72" SL bucket, and 84" JD snow blade, mid PTO....oh and double real wheel weights. i did not like the R4s my 4720 came with and invested in new rims and tires getting the R1s. R1s are better with hills on snow and in wet/mud areas - if you are buying new, you'd want to get this worked out before you buy...it's much cheaper that way. i think there are other discussions on this site comparing these two units. if you are mowing hills using a rear mower, i found my front suitcase weights very helpful in keeping the front wheels on the ground - of course i always mow up and down steep hills rather than sideways. when mowing up and down steep hills, 4WD and A (low) has helped from a "run-away" ride.

jloven · Feb 19, 2015

I noticed a significant Increase in PTO power on the 3720 vs 3320. I needed the extra power for mowing on some hilly terrain and operating a chipper. I would only consider stepping up to a 4520 or 4720 so I could get more HP.
My question now is how difficult is it to tow the 4x20 tractors? I have a 7000# rated landscape trailer that I use to move my 3720, but it is maxed out with the tractor and an attachment like a backhoe. What type of trailer would you need? I can't invest in a gooseneck since I don't have a truck. I use a suburban with towing package.

jenkinsph · Feb 19, 2015

I have been using a bumper pull 12k Big Tex for the last 10 years, works OK with a 3/4 ton truck or similar. I use an F550 most of the time to move my stuff and that handles it better.

AKfish · Feb 20, 2015

What Category is the hitch on your Suburban? If I had to guess, I'd guess it's a Category III which limits you to 7,500lbs. By chance, you might have a category IV and that would take you up to 12,000lbs.

Most bumper pull trailers in the 10K-12K range will weigh between 2,000-3,000lbs. For napkin calculations; 2,500lbs.

So, category III with a 10K-12K trailer gives you a cargo load of 5,000lbs. Would'nt matter which trailer. The hitch is the determining factor.

Category IV hitch with either a 10K-12K trailer gives you a cargo load of 7,500-9,500lbs. IMO - the 4720 with loader and mower attached is gonna be very close to 7,000lbs.

Final question is: what is the Gross Combined Weight Restriction (GCWR) for your Suburban? Suburban=6,200lbs? Trailer=2,500lbs. Tractor=7,000lbs. Gross Combined Weight = 15,700lbs.

Suburban GCWR has to be greater than the estimated Gross Combined Weight.

AKfish

Fallon · Feb 23, 2015

Trailer axles are generally 3.5k or 7k lbs. That means the trailer will be rated at around 7-7.5k or 14-15k lbs when you figure 10-15% of the weight should be on the hitch. A 14k lbs trailer usually weighs in the ballpark of 2k lbs on its own.