Why are Kubota FEL's so weak?

[rScotty]

Our Kubota M59 seems to lift within specs. It is rated at 4000# at the front bucket pins and half that at the bucket lip. Last Fall I picked up a 10 foot length of 30" concrete pipe by dangling if from chains running from the bucket hooks over the bucket lip and around the pipe. Then carried it with the bucket curled half a mile to where it was to be used. There's not much guesswork on the weight - that size pipe weight should be 2190 lbs. I was careful to take my time, go slow, and not let it get to bouncing - but that load is just within Kubota's operation specs. To the surprise of the swamper - and to my own relief - the tractor handled it without strain. Steering and balance seemed not much different from normal.

Over the years I've noticed that where this loader could stand improvement is in the bucket roll-back force when the lip is held in the neutral horizontal position - that's the most common position when sliding the bucket into a pile to load it. The bucket roll-back force in that position is adequate, but that's all it is.

I see no simple reason that roll-back force couldn't be designed to be a lot higher. After all, it's a local force out at the tip of the loader arms and doesn't stress the tractor or loader mountings. It might be deliberate though - for instance the real limitation might be the strength of the SSQA adapter. Maybe I'll look at that....

Hmm....I just looked at the "specifications of the loader" on page 7 of the operating manual where Kubota shows drawings of the geometry they used to calculate the loader forces. The drawings of the bucket linkage geometry are not correct, and that means any force calculations based on that geometry are also incorrect. If that page originated from the design group, it would help explain the odd weakness in the bucket roll back force.

Oh well, I guess it doesn't really matter. That's all theoretical stuff and worth what it cost. There's plenty of muscle in that loader for anything we've wanted done.
rScotty

 

[majorwager]

Several points,
First most of the postings reference compact tractors. They are NOT full frame/chassis tractors. Think about where this weight is supported. Typically it is the bolted joint between engine/transmission, sometimes an additional reinforcement toward the engine front.
Honestly, a ton should be a maximum lift pin weight. It was noted, machines designed to lift are configured entirelly different. I have two lulls and a hyster. They are full frame machines, weight borne on chassis, not engine/trans components. Reach the max limit you can obtain, you will then own a two piece tractor, a mirror will produce the responsibie party. Manufacturer will likly claim abuse. Court dockets abound with similar dispositions.

A word about ballasted tires. Too many presumptions here. Folks tend to accept for granted, proper levels, but what material was used? And to what volume.
Calcium, beet juice, antifreeze, washer fluid, tap water, produce different results. Do you know what concentration was used? Are tires filled to 75 percent? Ever confirm? Ever look at the chart to know how many gallons each tire contains? Know weight per gallon, your solution concentration?
Lots of folks making presumptions, My tires are loaded!!! Really? You were there? I just checked tire level in a tire because liquid fill valve had aquired a small leak. The tire was filled to +90 per cent. Are both tires filled to same level? This isn't a fun job. Did the novice with nose buried in cell phone get it right? I know, I believe you, your tires are "loaded"

 

[Ortimber]

I am glad the L series tractors don't lift more. I think that they are already too light for the amount they can lift. Using the tractor safely on less than flat ground is touchy. I've got filled tires and a heavy box blade for ballast.

 

[oosik]

There is a very simple, easy and accurate way of checking how much ballast is in your tires. Take a day like I'm having today - cold - 37 F and high humidity - 80%. Go out there and look at your rear tires - there is going to be a very definite "moisture line" on your tires. Above this line is air - below this line is whatever is ballasting your tires. My "moisture line" is exactly one inch higher than the top of the rim of the tire. This is approximately 75% filled or with the Rimguard in my tires equals right at - 69 gallons/tire or 738 pounds of RG per tire.

There is a very simple chart at the Rimguard web site that lists how much any tire size should be filled.

 

[mikester]

I am glad the L series tractors don't lift more. I think that they are already too light for the amount they can lift. Using the tractor safely on less than flat ground is touchy. I've got filled tires and a heavy box blade for ballast.

+1

I don't think people are being realistic expecting to lift heavy loads with tiny tractors and then complaining about crappy specs.

If you need to carry 3,000 lb loads all day long then don't buy a machine at its max rated spec.

I can pick a load that'll lift my rear wheels off the ground....what's the point? Earn another stripe in the underpants?

 

[rScotty]

Several points,
First most of the postings reference compact tractors. They are NOT full frame/chassis tractors. Think about where this weight is supported. Typically it is the bolted joint between engine/transmission, sometimes an additional reinforcement toward the engine front.
....SNIP.....

Got to agree with that....or at least part of it. In the 1980s my friend had a tractor dealership and he never tired of pointing out that at his shop a full length sub-frame for a loader was part of the OEM factory supplied loaders even for the smallest compact tractors - which at the time was a 15 hp Yanmar. Yep, that little tractor just about defined "basic", but it did have a heavy full frame factory loader.

The OEM factory loader with a good sub frame did cost more, and Dan was always trying to convince customers that it was worth their money to go with the factory loader. He wouldn't sell any other kind.

There were other dealers & rental yards nearby that sold after market loaders because they were cheaper. So we got to see lots of those. They were mounted just as you say - most used the forward engine mounts in front and the bell-housing or a cast iron engine/transmission lug for the rear mount. There was no separate loader sub-frame; instead, the engine\bellhousing\transmission case was used as the loader frame. Bad Idea, & breakage was common for that type loader. I doubt there are many of those left.
rScotty

 

[David_Kb7uns]

If a Kubota loader is weak, how did it lift this??

David

 

[DK35vince]

If a Kubota loader is weak, how did it lift this??

David

That looks pretty strong to me.

 

[Garandman]

Where are the curves from the other brands?

 

[LD1]

Where are the curves from the other brands?

Only place I have ever seen lift curves published is in the loader manual.

and since I have only owned kubotas....I havent seen other brands' manuals....so dont know if they are in there or not.

Even the kubotas isnt published online anywhere that I can find