L3902 very tippy what am I missing?

   / L3902 very tippy what am I missing? #1  
Joined
Mar 14, 2016
Messages
49
Location
Tennessee
Tractor
Kubota L3902; Kubota b7100HST
I have an 2023 L3902 I got at the beginning of June. I got R1 tires w/fluid set at the middle width setting on it an FEL, rotary mower and a rototiller. My last tractor was an 25hp LS with R4 tires w/fluid FEL and a detachable factory backhoe both this tractor and the LS are the same physical size only difference obviously is the engine size and the tires. However this tractor is so tippy I can't even pick up a bucket load of gravel without the tractors rear end coming off the ground. The LS had no problems completing the same task. I've almost dumped this tractor 4 times now doing meanial tasks that should not cause a tractor of this size any issues. The only was I've managed to keep it from tipping is to have my rotary mower attached and as low as I can get to the ground all the time. But even then it's still feels unstable. What am I missing or is this the way they are?
 
   / L3902 very tippy what am I missing? #2  
I have an L2501 with fluid filled tires and the standard bucket. My experience is I really need to at least have a box blade on the 3pt when doing any FEL work. Not having anything on the 3pt is a no go.
 
   / L3902 very tippy what am I missing? #3  
What model LS did you have?

The Kubota is 2,700 pounds bare tractor weight.

Let us determine the exact bare weight of your prior LS.

The LS Backhoe would be much more effective counterbalance than either a Rotary Cutter or a Roto-tiller.


I got R1 tires w/fluid set at the middle width setting.

Increasing the spread of your tractor rear wheels is the most effective way to increase stability. Many L3902 owners install aftermarket rear wheel spacers.

 
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   / L3902 very tippy what am I missing? #4  
Sorry, but just to clarify a few things. Both tractors had rears filled 1/2 way? Doesn't sound like the new tractor came with a B/H, presumably you're comparing each with B/H off? A heavier FEL with larger bucket would put more weight out front.
Stability ends the moment just one of the rears comes off the ground - when the load forward of your front axle pivot is greater than the tractor weight behind it. Think of a triangle made up of the front axle pivot and the contact points of each rear tire. The minute a vertical (or plumb bob) from the center of gravity for the tractor plus implements plus bucket load moves outside that triangle - over you go. This is why working a slope is even more dangerous and you should always keep your FEL load as close to the ground as possible. Adding weight, as far back and as low to the ground as you can put it is the best counter to a loaded FEL. There is a point where too much too far aft will pull the front axle off the ground (a B/H grappling a log going up hill) but that's usually not problem for most. A belly mower helps, a couple of hundred lbs. (if that much with them 1/2 full) in the rears is better, 200-300+ lbs of rear implement better still, but 800-1000 lbs. of frame mounted B/H hanging off the rear beats anything you can do to improve stability with a loaded FEL.
Max stability is when the tractor's combined CG is over the center of the rear axle and as low as possible.
 
   / L3902 very tippy what am I missing? #5  
I have zero experience with the LS. I have bunches with Kubota. In my opinion the Japanese have NEVER really understood what working on steep ground meant nor how many of their customers care. The K brand is simply the WORST in terms of poor choices for widening the rear wheels and therefore stability on steep ground. Always has been. Some of the larger M series now appear to be ALMOST there in terms of available adjustment for rear wheel width. Close, but not yet as good as Massey or New Holland or Deere. Just read the dimensions.

Now off that rant/soapbox let me suggest: exactly as Jeff said above -- get yourself some rear wheel spacers. I use 6" on each side on a B2150 which converted it from turnover prone to safe. I see both an L3400 and an M6040 being used by my friends on steeper ground in the WV hills. They have been using dealer-installed spacers of 2 different brands/style and both work well. I use the Bora brand I installed and find them very good. Well made, well thought out.
 
   / L3902 very tippy what am I missing? #6  
What? My L-2501 is used lots for moving gravel, bucket full loads. Never had an issue with rear wheels coming off the ground or even close. Of course the rears are filled with beetle juice and I do this work both with and without the rear mounted flail mower attached.
 
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   / L3902 very tippy what am I missing? #7  
Have the rims widened to their maximum, get the correct amount of fluid in the rears (75%), and always have ballast on the 3 point when doing loader work.
 
   / L3902 very tippy what am I missing? #8  
Now you understand the need for counterweight. It is needed for loader work with any tractor this size regardless of color or whose name is on the hood. I believe the manual also has some language to this same effect.
 
   / L3902 very tippy what am I missing? #9  
Just to clarify; Spacing out the rear wheels will aid stability sideways, but a little visualization will make it clear that it will not help your fore and aft stability. For this you need a counter weight behind (backhoe, etc.), which is most effective, or more beet juice or wheel weights.
 
   / L3902 very tippy what am I missing? #10  
You need a wider set rear wheels. That means spacers or dual wheels. Spacers are low cost, duals are pricey but add traction as well as being very stabile. Use quick-release type and air only ,in outer tyres, and ballast the inner tyres. I used to remove the outer right tyre for mowing and baling hay.
Are you using a standard or oversize bucket?
 
 
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