Just bought 4720 cab and unhappy with hill ability

[osu s2k]

I recently picked up a loaded 4720 cab, radio, light, weights, ect and was bushhogging the last few days and am unhappy with the instability and potential rollover feel i get on hills. I also have kubota 3130 and feel more steady over the same terrain. I may be looking to sell however will be taking a pretty big loss.

 

[jcmseven]

I have found the 4000 series to be very stable on hills. I am not sure why yours is not. The key is to weight the machine as much as possible, loaded rears (and fronts if needed), weights if possible and have the dealer invert the wheels. This would make for a very stable machine, on virtually any slope one should be on. I am not familiar with the Kubota line but isn't the 3130 a little smaller? This would give the perception of being more stable, but it might not truly be. I currently have a 3720 JD and my neighbor has a 241 (old) MF. The Massey when I have used it FELT more stable because I sat lower in it and it has bigger diameter tires. Unfortunately though it has fishtailed on me twice when using it, and my 3720 easily handles the same slopes in four wheel drive and does not budge. Interesting, in this case the perception did not match the actuality.

John M

 

[BloomingtonMike]

I was out mowing my steep hill sides today and I was thinking about the number of times I use that grab rail on the fender. What do you grab in a cab. I would think I would be pinned against that cab glass in a few spots. Be careful!!

 

[Neophyte]

Do you have loaded tires on your 3720 or 3130?

Do you have an FEL on while bushhogging or are you using front weights on your 3720 and 3130?

Do you have a tilt meter on either?

Keep in mind that the cab model weighs about 700 lbs more than the open-air model. I would bet that a good part of this extra weight is above the tractor's CoG (center of gravity). I would imagine this is a potential disadvantage to any cab tractor.

I believe the 3130 weighs around 3300 lbs, 300 lbs less than the 3720 cab, and has a rear wheel track of about 58" max.

 

[osu s2k]

Rears are not loaded and i did buy the weight kit, i never thought about inverting the rear tires, so i guess inverted tires, weight the tires and weight the front should be a lot better, thanks.

BTW, i grab onto a handle in the cab, the pucker factor goes really up there.

 

[dirtworksequip]

osu, I have a JD 3520 w/cab. As soon as I started to use it I felt the rear wheel stance was too narrow. I had the right rear tire off the ground about 5 inches while mowing and had to pull it out of this position with a Cat tracked skidsteer. I then ordered 4 inch wheel extensions from Unverferth. The biggist drawback with them is they are expensive ($720.00) With the R4 wheels you can only gain a couple inches by moving them to the wide position. If you have R1's those wheels change into several configuations and should give you a wider rear wheel stance. I ended up with a 66 in rear wheel track which made the 3520 alot more stable. I could take my old JD 870 places I would never think about going with the 3520. Each tractor is different, so be careful. You may not be able to go into one with one tractor that you can go with the other.

 

[Neophyte]

I then ordered 4 inch wheel extensions from Unverferth. The biggist drawback with them is they are expensive ($720.00) With the R4 wheels you can only gain a couple inches by moving them to the wide position.

Dirtworksequip, do you have any pictures of this setup? It would be neat to see these and a picture of the wider stance from the rear. Did you put wheel extensions on the front and rear, or just the rear?

Unverferth Agricultural Wheel Systems - Wheel Extensions

 

[JWaterstreet]

I bought my 970 used from a guy that has owned a number of JD CUT's He had just bought a new 3520, and he was really concerned about tipping. He said that he almost flipped his new 3520 on a slope that the 970 handled without issue. He also had a couple of 4000 series tractor (I think a 4310 and a 4520) and would not even drive them on a slight grade. (he said he had rolled the 4310 once)

I would think a cab tractor would even be much worse.

So in this guys opinion, the 870/970/1070 series are most stable, the 3000 series are worse, and the 4000 series are the pits. I personally think you can't generalize though, because of variances in tire size and stance.

BTW, I have berms that range betwee 15 and 20 degree slope. The 15 is no issue, but I get concerned with the 20 degree slope, and hang onto the uppermost fender handle. I just make sure the mower is on the ground and the FEL just off the surface. Probably most important, the seatbelt is on and tight.

Jeff

 

[jcmseven]

I do not think the 4000 series you are mentioning is the culprit. The 4520 I had was extremely stable, but was not a cab model. The grades I have I would stack against any around for abruptness and steepness and my 4520 did fine. The cab might be the hinderance here, so our goal would be to move the COG lower on the machine by weighting it. Also, we are talking a 4000, not a 3000 series. The dish on the rear wheels is greater with the 4000 series so simply inverting the wheels would do alot, without the expense of a wheel extension kit. My neighbor has his 4320 with inverted wheels and it is quite a bit wider stance (he runs a backhoe). One could try that though if it still was not stable enough. There is a major stability difference between the 4000 series and the 3000 series and the 4310 mentioned would be closer to the current 3000 series. My 3720 is a great machine, but it is not as stable as my previous 4520, which when weighted appropriately was fine on some nasty steep hills.

John M

 

[Superduper]

Obviously, a cab model is going to add substantial weight higher up which will definitely affect center of gravity. In this case, the cab adds 635 lbs, I imagine virtually all of it above wheel height. I have seen cab models and marvel at how narrow they appear. Personally, I would never operate a cab CUT on anything but moderately flat land. This applies for all makes and models, not just deere. The size of the cab just appears to overwhelm the size of the smaller tractors, and proportion wise, already looks like it's tipping even on flat ground. Of course perception is not always reality. On the other hand, one never knows if the fear is founded or not until you actually tip it over.

Filled tires will help the situation but my guess is that no amount of weighting will counteract the increase in center of gravity. It's clear that adding as much weight as possible at the wheels will help to stabilize the tractor. The weights at the corners have a leverage effect. Widening the track will certainly go a long way towards making it more stable -- the wider, the better. You already have the weights, which are expensive. Filling the tires, especially if only water is used, is free.

As far as pucker factor goes, sitting higher up will always give the feeling of greater instability, whether founded or not. I imagine that if you sat at the top of the ROPs, even a 5 degree tilt would feel highly uncomfortable. I'm certain that this is the reason for the additional puckering when grab handle is pulled. Given that the tractor weighs over 5000 lbs as operated, shifting your weight probably isn't going to affect the COG much.