Comparison 3000 series or 4000

[Tritonman]

I am starting to look at a new tractor, and am having a tough time deciding between the 3720 series and the 4720 series. What are the main differences, other than the obvious. Are the rear ends the same, etc.

[Nuru]

What size property are you considering the units for? We need to know that so we can discuss.

[jenkinsph]

Tritonman,
The 3000 series uses a spur gear rearend and the 4000 series uses a planetary rearend as the larger tractors do.

[radman1]

I had a JD 3720 and now a JD 4520. Both had cabs and fairly loaded. The rear ends are completely different. The 4520 is a little longer and little taller at the hood.

The 4520 has significantly more clearance in the rear. The 3720 with R4s had about 8" clearance at the drawbar and the 4520 is closer to 15-16" with the R1 tires. However, the R4 tires are not that much shorter than the R1 tires on the 4x20 series. Bottom line, the 3720 with R4 tires, was not good in deeper mud. No traction and no clearance. This was probably the biggest reason I traded up.

The 4x20 has much greater stability on slopes. The 3x20 series is only 60" wide and seemed tippy. The has been noted my many other owners. The cab also accentuated the problem/sensation.

The 4x20 has more of an engine knock than the smoother 3x20. The noise of the Jd power tech engine is noted by many owners and is similar at idle and higher rpm. The 3x20 uses a quieter yanmar engine and noise is similar to kubota or NH/Case-IH. However, with cab, the inside noise is not significantly different between the JD series.

More power of the 4520 is more noticable when traveling in road gear. The 3720 would slow going up hills.

The 3 pt range of lift is better with the 4x20. This is in part due to longer lift arms on the 4x20. Easier to lift implement higher.

Both had the air seat but the 3720 rode harsher. Probably due to smaller tires, narrower width and harder sidewall of the R4 tires.

The 4x20 series has the optional self-leveling FEL which is not available with the 3x20 series. The FEL lift of the 4x20 is also significantly more.

[Tritonman]

Thanks guys. I want something that can straddle two 30 inch rows to go with my four row corn planter. I could put spacers on the 3720 but going with the next series up seems to be the ticket for me. The rear end question was the big one for me.

Could a guy pull a disc all day with the 4720 with no ill affects. Something like an 8 footer. I know its not as good as a gear shift for this application, but definately want to stick with the hydro.

[beenthere]

Originally Posted by Tritonman

I am starting to look at a new tractor, and am having a tough time deciding between the 3720 series and the 4720 series. What are the main differences, other than the obvious. Are the rear ends the same, etc.

I believe the main difference is the frame size. Then the engine size....etc.

[radman1]

I have my 4520 with R1s set for 30" rows. I am not quite in the center of 30" rows but slightly narrower. I left the tires slightly narrower so my overall rear tire width was just under 72". I have a 6' rear mower and 6' wide bucket and wanted to keep under 6' tire width. I could have placed each tire 2" wider on each side (max width) but it was getting too wide for me.

If you are doing row crops, definitely get the R1 tires. They will have the adjustable rims for tire width. My understanding is the new R4 rims no longer have the bolt on rim adjustability. Also you will want/need the R1's for traction, mud ect.

Can the 4720 series handle the 8' disk? I think so. It has the power but does it have the traction? With rear end weights probably. I bought a used landpride 6', 3 pt last summer but have not tried it yet. Is the 8' a 3 pt or pull type. If 3 pt, how heavy is the disc? IMHO, I wouldn't want a hydro tranny pulling hard all day with a disk. The heat production would get really high. I would guess, a HST tranny is 10-15% less efficient than a gear drive. The loss of efficiency is produced as heat.

[jenkinsph]

Originally Posted by Tritonman

Thanks guys. I want something that can straddle two 30 inch rows to go with my four row corn planter. I could put spacers on the 3720 but going with the next series up seems to be the ticket for me. The rear end question was the big one for me.

Could a guy pull a disc all day with the 4720 with no ill affects. Something like an 8 footer. I know its not as good as a gear shift for this application, but definately want to stick with the hydro.

Short answer is yes, I have never had an overheating issue with either the 110 or 4520 under high draft loads. Pulling an eight foot disc I don't think you will see much difference between the 4520 and 4720 and would remind you the cooling systems are identical, so I can say for sure the 50 to 60 hp output settings I have had no problems with.

[johndeere4720]

Could a guy pull a disc all day with the 4720 with no ill affects. Something like an 8 footer. I know its not as good as a gear shift for this application, but definately want to stick with the hydro.[/quote]


A 4720 would have no problem with a 8' disc, in fact you could go 10' or 12' and you wouldn't have any trouble.

Here is my setup that can pull a 10' disc all day long in heavy clay without a problem.

[Tritonman]

Nice looking setup. How many weights do you have on each tire on the rear and how much weight is that.