What should my rear ballast weigh ?

[sailorman]

Really great info. comin' from ya 'll. I 'm gonna change my approach based on advise and what I 've been able to determine from my manuals. Manuals : 1 ) no specific ballast weight is reccomended for loader except the max weight off 660 # on lower links of 3ph. Just says may vary by job. 2) various implement weights are suggest if used for ballast. 3) filled tires are suggested also, but that 's a little too permanent for my purposes.

New approach : 1 ) continue to save bucks for needed box blade and use it with added weight when needed. My bush hog weighs more, but will hinder manuvering in tight spaces. 2) us my carryall rig with scrap weight while saving bucks. 3) experment with different weights until I learn the sweet spots for jobs.

Anything I 'm over looking in this approach ?

 

[LD1]

I would first question why your manual says 660lbs max.

Kubota lists the 3PH specs @ ~1300lbs at pins and ~1000lbs @ 24" back. Allthough I doubt you could keep the front end down without the loader on.

Idealy you want enough ballast out back that the loader cannot lift the back of the tractor. This is easy to determin by trying to lift something that's too heavy. Like an old vehichle or geting the edge under a large rock. If the hydraulic relief opens and the rears are still on the ground, you have enough weight.

For your size tractor, I think somewhere between 500 and 600 lbs should do the trick. 60lb bags of cement make 1/2 cu ft. And cured it weighs 150 per cu ft as already mentioned. (yes a lot of water stays behind. Concrete has a really high moisture content, kinda like green wood).

So you need about 4 cu ft of concrete. Thats only 8 bags which menards around here usually has 4 for $10. So for $20 you have yourself a nice counterweight.

On a side note, I am not sure I quite understand how you plan on using the cardboard tubes. If you plan on laying it on it's side, I'd recomend aginst it. It will like to roll around and not stay in one place from time to time. A 600lb cylinder of concrete rolling your lawn all by itself probabally wouldn't be good.

If you have access, and maybe save a little money (them tubes are $$$) get a plastic 55gal drum. They are about 22" diameter so they will fit between the 3ph arms. 4cu ft = 30 gallons. So cut the barrel off @ 18" up from the bottom and drill holes in the side, and shove the lift arm through. May also be a good Idea to weld an upright to tie into the toplink, if you so choose. And I'd wrap the lift arm with some old wire/fencing if you got any to get rid of.

Here is a link like what I am describing. Just shorten the barrel accordingly.http://www.tractorbynet.com/forums/build-yourself/164889-simple-three-point-counterweight.html

 

[sailorman]

I would first question why your manual says 660lbs max.

Kubota lists the 3PH specs @ ~1300lbs at pins and ~1000lbs @ 24" back. Allthough I doubt you could keep the front end down without the loader on.

Nice info LD and thanks for taking the time to reply. Good suggest on using the drum. I 'll definitely look into that. So far I haven 't been able to locate drums in my area.

Your answer has brought up more questions that follow and I hope you might find the time to answer.

Quoting my manual, Lower link end max. loading weight 660 lbs. Now if I misread and it means per arm then it would be 1320 lbs which is close to what you say. Is that what I did ?

Yes, I did plan on tube on side. But, I don 't understand what you mean by rolling my lawn. Do you mean if weight contacts lawn it would roll ? If so, I would have it raised up not on the ground.

Could ya give me a little more info on that lifting an old vehicle thing ? Do you mean I should have ballast on, try and lift the vehicle, and see if the relief valve kicks in so tractor rear stays on ground ? And is the relief valve related to the term breakout force. Is that the weight of a lifted object that will cause the relief valve to function to prevent rear end lift and damage to loader or tractor ?

 

[LD1]

The rolling the lawn was kinda a joke. Meaning that if you try to unhook it on unlevel ground, it may get away from you. Like parking your tractor on a hill in neutral with no brakes set:confused2:

As far as what your manual says about 660lbs I don't know for sure. It depends on just how it is worded. But I find it odd if the max is 660 and kubota lists the spec @ a little over 1300lbs rear lift.

As to what I was saying about lifting a car and the relief and all that:

Idealy, for saftey, you don't want your loader to be strong enough to lift the back tires in the air. The only way to do that on these small light machines is with rear ballast. Your hydraulic system will only develop about 2500psi of pressure(I don't know the exact spec). With no weight on the rear, that is enough force to lift the back of the tractor in the air. That transfers the entire weight of the loader, tractor, and whatever you are lifting onto the fron axles. Thats just too much stress on them. The more weight you have out back, the less weight that gets transfered to the front, as more of it stays on the rear.

You mentioned you had a carry all. Assuming it weighs about 100lbs, load it up with about 500lbs of whatever you have, and try to lift something with the FEL that you know is too heavy to lift. If the back tires raise into the air, you know you need more weight. If the back tires stay down, and the whatever you are trying to lift doesn't budge, that means your loader relief valve is kicking in and you have enough ballast. But also keep in mind that 500lbs of ballast hanging back about 24" on a carryall will do more than 500lbs right at the pins. It's a leverage thing.

 

[sailorman]

The rolling the lawn was kinda a joke. Meaning that if you try to unhook it on unlevel ground, it may get away from you. Like parking your tractor on a hill in neutral with no brakes set:confused2:

As far as what your manual says about 660lbs I don't know for sure. It depends on just how it is worded. But I find it odd if the max is 660 and kubota lists the spec @ a little over 1300lbs rear lift.

As to what I was saying about lifting a car and the relief and all that:

Idealy, for saftey, you don't want your loader to be strong enough to lift the back tires in the air. The only way to do that on these small light machines is with rear ballast. Your hydraulic system will only develop about 2500psi of pressure(I don't know the exact spec). With no weight on the rear, that is enough force to lift the back of the tractor in the air. That transfers the entire weight of the loader, tractor, and whatever you are lifting onto the fron axles. Thats just too much stress on them. The more weight you have out back, the less weight that gets transfered to the front, as more of it stays on the rear.

You mentioned you had a carry all. Assuming it weighs about 100lbs, load it up with about 500lbs of whatever you have, and try to lift something with the FEL that you know is too heavy to lift. If the back tires raise into the air, you know you need more weight. If the back tires stay down, and the whatever you are trying to lift doesn't budge, that means your loader relief valve is kicking in and you have enough ballast. But also keep in mind that 500lbs of ballast hanging back about 24" on a carryall will do more than 500lbs right at the pins. It's a leverage thing.

Now that is very clear to me. Over looked the roller joke. Wish I hadn 't 'cause I can just envision the pandemonium that would cause now that you pointed it out ! Fortunately I 'm a flat lander.

My carry all is customized with a platform and I would be sure to stack weight as close to the life pins as possible to dampen leverage situation. I got the perfect junk trunk in yard to lift ( the red neck in me ) .

And the relief valve prevent loader damage while running this test ?

Thanks a billion !!

 

[LD1]

And the relief valve prevent loader damage while running this test ?

You shouldn't be able to do any damage at all. We have all tried to lift things that our trators wouldn't. Like digging out stimps, or trying to pry out rocks, etc. Only one of 2 things should happen if you try to lift something too heavy.

1. Your rears will lift
2. The relief will bleed pressure.

There should be nothing to damage on the loader. If something isnt structurally strong enough to handle the 2500psi the tractor makes, then kubota would have designed it differently.

 

[sailorman]

Only one of 2 things should happen if you try to lift something too heavy.

1. Your rears will lift.

:laughing: Did that one right out of the gate. Scared the you not what out of me. Let that loader down real quick :laughing: .

Thanks for the help :thumbsup:

 

[texasjohn]

A clue that works for me in determining total weight needed in rear....

Rule 1..... weight should be sufficient (as mentioned before) to keep rear wheels firmly on ground when FEL hydraulic relief valve is open because weight limit is reached.

Rule 2......with almost max weight on FEL (for me this is 2800 lbs which I can raise to a height of about 1.5 foot before relief valve opens), be able to drive at reasonable and safe speed over reasonable ground without rocking back and forth significantly. Point is, if you have barely sufficient weight to keep rear wheels on ground while parked, then when driving over necessary irregularities the nose will dip and you will feel the rears lighten up or actually leave ground contact. If this happens, continue to add rear weight until the entire tractor feels "solid on the ground" while fully FEL loaded and driving reasonably. I know when I have the proper balance...it just "feels" right while driving. Don't worry about putting too much weight on the rear, all tractors I know of can lift far more weight in the rear than they can in the FEL.

 

[Deerlope]

Adding ballast weight to the 3PH is just about the most unprofessioal thing I have ever heard of. In time it will do damage to the dirveline and bearings. In the tire ballast is the answer.Tire ballast put the wieght on the ground not on the bearings and driveline. You 3PH is always open of use.

 

[LD1]

Adding ballast weight to the 3PH is just about the most unprofessioal thing I have ever heard of. In time it will do damage to the dirveline and bearings. In the tire ballast is the answer.Tire ballast put the wieght on the ground not on the bearings and driveline. You 3PH is always open of use.

You are absolutly crazy. Who cares what's "professional" and whats not. We are just home owners that have small tractors to maintain our property.

Hey maybe he should just leace his tractor sit in the garage and never use it at all. Because that would put hours on it and wear things out eventually.

Tire ballast is NOT the answer on SCUT and CUT tractors. It will help but the tires just arent big enough to give enough ballast. And once in, it's permanent and many on here use their CUT of SCUT to mow their lawn, where the weight is not wanted. If we were talking a farm tractor that only sees field work, then that would be a different story.

The OP could do as you suggest and load his tires and not use any rear ballast as it is "umprofessinal". And when he goes to move a full bucket of clay, or gravel, or whatever, and the rears are in the air, and all the weight is on the front axle, doesn't that wear things out a little quicker than say......putting 600lbs on a 3ph designed for 1300lbs??????:confused2: