You need balast or you will trash your front axle!!!! really?

[gladehound]

I think the key to making sure you don't trash your front axle is to use THIS much counter balance...

View attachment 458311

Obviously this is a very conscientious operator, thinking to fully protect his font axle in this way.

 

[square1]

I'm getting a headache!

Try hanging some ballast off yer butt and see if it relieves some of the pressure from your head

 

[chopped]

 

[brown40]

Wow--thats a lot of reading for a simple question!
Bringing up the "dynamic" vs. "static" load situation is the biggest reason I like to have plenty of counterweight. Its rare I get to work on a level surface, so there are "moments", when the loaders full and a front wheel dips, that the cumulative forces on the tractor shift towards that wheel. Its that dynamic loading of a component (tractor front axle) thats meant to "assist" with traction that concerns me the most.
The axle rating on the rears typically dramatically eclipses the front, so the more "preventative unloading" of the front axle I can have in place hanging weight off the 3pt, the less it'll encounter during my "moments".
Great thread, and especially good for newer operators who assume ballasted rear tires are a suitable replacement for adequate counterweighting. It is not. You will lose rear tire traction and shift you balance point forward far more often with 1000# of ballast in the tires and no counterweight than you would with unballasted tires and 1000# hanging 24" off the back. Simple physics, but sometimes difficult to grasp. Hope I didn't just open up another can...

 

[RalphVa]

Most stable load I've carried is with the loader full of mulch in the front and the carryall about 1/2 full in the back.

The counterbalance works from the center of gravity, not the center of the rear axles. CG is in front of the axles.

Ralph

 

[rd_macgregor]

Ralph, I don't think that is right. While counter weights will change the CG toward the rear, the fulcrum (rear axle) is the relevant pivot point for unweighting the front axle. So, the total tractor+load increases with a counterweight, but the load distribution between front and rear axles shifts more toward the rear, for a net reduction in load on the front axle.
I think the dynamic loading issue is a much more critical one...but they are linked: if you are moving too fast on rough ground with near-max load in the front, any dip or bump might overstress the front axle components. If this happens with the wheels turning (eg steered to one side), I think the probability of damage increases further still.

 

[CalG]

It certainly does, but the counter weight is factory. In this situation the counter weight would make very little difference to the front axle since it rides very close to the rear axle. With no load on forks the rear axle is carrying nearly double what the front axle is. According to the chart on the side there is still 2,600 pounds on the rear axle with rated capacity on the forks and 15,000 pounds on the front axel with rated capacity on the forks. Now that how much that is when those solid wheels hit a bump.

F=MA, I'll leave it to you to fill in suitable numbers. Bump profile and wheel radius along with forward velocity determine the vertical acceleration one might experience during a "bump".

Bump has nothing in common with "squat", unless you choose to use the words interchangeably. I prefer to use them to describe two different conditions.

Squat being the compression of compliant elements due to loading.

 

[Snowback]

In all seriousness, please do take the suggestions of the helpful and knowledgeable posters above who are correctly encouraging everyone to use appropriate counter balance when doing loader, fork, or grapple work. It absolutely WILL remove stress from your front axle and make the operation much safer. The only way to be able to utilize your loader's full lift capacities safely and with minimal undue mechanical stress is to have good counter balance/weight, especially if you have a lighter tractor with less built in weight. I love the diagrams and models too!

Also - please note that 1) ballast, and 2) counter weight/balance, are not one in the same. Loaded tires or axle weights provide ballast which is additional weight on axles or ground, and this aids in stability, traction, etc... In order to properly use a loader, or a rear mower in a machine without a loader, one should apply weight either rearward of the rear axle to counter balance the loader stress on your front axle, or perhaps put suitcase weights on your front end to counter balance the tendency of the front end to lift off the ground when mowing or pulling a 10 ton trailer like the guy in the picture above.

It's not a simple concept and building a quick model might be helpful, and fun if you have kids! For those who are interested but are not physicists or engineers that understand this due to education and everyday application of force, vectors and moments, try this one on for fun.

Take two thread spools and tape Popsicle sticks across the top of each. You now have two teeter-totters. Next, overlap the Popsicle sticks a bit and tape them solidly together. You now have a representative model of your tractor. The spools represent the front and rear axles which are the fulcrums, or pivot points. You can use your fingers to test loading scenarios and and use small weight scales to show how the moments and application of force at differing distances from the front or rear axles cause changes in the relative loading of the front and rear axles as you shift the center of gravity back and forth. Every time you lift either the front or rear spool you will have found the scenario that moves the center of gravity just past the opposite axle and then places all of the weight on that other axle/spool. You could put a ton of weight over and beyond the front spool, but as long as you apply a sufficiently heavy counter weight past the rear spool, you will have NO additional force imparted to the front axle. As others have correctly stated there are nuances when motion is introduced, but if properly counter balanced they will never cause problems. Only if there is a catastrophic shifting of CG (center of gravity) due to load shift, or perhaps your rear counter weight getting hung up on a hill or ditch would you see any risks. Operate safely and it should not be a major concern.

Proper counter weighting will allow you to break your loader frame before your front axle ever gives up, and that probably only happens if "bulldozing" where you can apply more force to the loader than it was designed for. Finally, to tie this together from a semantics standpoint, one can use "ballast" in a "counter weight" application. It's just that the ballast must be placed behind the rear axle, or perhaps in front of the front axle to be able to properly counterweight the forces affecting the opposite end when pulling a heavy trailer or rear implement.


Below is a good diagram that will demonstrate how your spool model will work. In Australia they recommend against filling radial tires for ballast... They also spell "tyre" wrong. I still think liquid tire ballast is best for basic stability and traction, but I have not used a tractor with radials tires, so maybe there is a point there.

Stay safe all!

https://www.worksafe.vic.gov.au/__data/assets/pdf_file/0009/12240/140861_Chorus_WS_Tractor.pdf

 

[Gary Fowler]

Great question? You've added greater weight load to the front axle so the rear wheels are no longer meeting the tractor definition of 2 axles and 4 wheels in ground contact. So adding ballast in the rear allows that definition to again work. HOWEVER . . . the weight on the front axle doesn't reduce if 2 axles and 4 wheels are in ground contact and you add 400 pounds ballast to the rear.

Simply stated . . I define the ONLY safe way to operate the tractor is with 4 wheels and 2 axles in ground contact so all stress changes made that violate that rule need to be corrected first. At that point adding weight to the front axle and tires is adding weight to those. If 500 more pounds or rear ballast get added and no change to 4 wheels and 2 axle contacts . . . you have not reduced the front end axle strain . . . unless you want to create a way you can have "more than ground contact".

Jmho

You must never have been on a teeter-totter. You couldn't possible think the way you do if you had. A tractor with FEL and rear ballast (behind the rear wheel) will act the same way. Just because the wheels are all on the ground, it doesn't mean that they continue to have the same force exerted on them as weight is added at either end. I have seen my fathers old 8N with all four tires on the ground but with such light force that turning the steering wheel had no effect on turning the tractor. By your thoughts, as long as all 4 wheels are on the ground adding weight to either end has no effect. You can put enough weight on either end that the tires are on the ground, but a 6 year old could lift the light end off the ground.
I just find it hard to believe that folks cant understand simple weight and balance problems when it comes to tractors.

 

[GolfAddict]

... I have seen my fathers old 8N with all four tires on the ground but with such light force that turning the steering wheel had no effect on turning the tractor. ...

Ah, but that's only because the rear tires squatted so much. If they had been steel tires, the only movement would have been a tiny bit from the ground squishing under them, so the front still would have been almost as heavy.

 

[4570Man]

Obviously this is a very conscientious operator, thinking to fully protect his font axle in this way.

That is what split brakes are for.

 

[bigdeano]

Anybody ever break a rear axle from too much counterweight?

 

[Agvg]

The limiter is how much you can lift, that I have seen is tractors break i half with heavy load on front and rear combined with high speed on the road, combined with a speed dump and a brutal driver it goes badly.

 

[gladehound]

The limiter is how much you can lift, that I have seen is tractors break i half with heavy load on front and rear combined with high speed on the road, combined with a speed dump and a brutal driver it goes badly.

My cousins JD4300 would break in half every ~1000 hours of use. He used it exclusively for back hoe work and to move pallets of rock that it could only lift a few inches off the ground. That tractor was never designed for that type of commercial use. However, it did have a good front axle. Never a problem with that.

I would think replacing a front axle would be a whole lot cheaper than fixing a tractor that broke in half!

I suspect different tractors have different weak points. As such, any general guidance to maximize longevity of a given model's various parts needs to be taken for what it is - general guidance.

In addition, with the limited number of failures as examples for specific models, it seems it would be nearly impossible to piece together supporting data to construct the best ballast plan for a person's tractor given that person's specific uses.

However, with ROPS on modern tractors, it is easy enough to tie the top of the ROPS to the loader frame via a FOPS/cage and help manage stress in the middle of the tractor from heavy weights on both ends. Since I've already taken this step, I suppose a counter weight on the 3pt is in order. Which means a quick hitch of some type is in order. Because without a quick hitch I'll never use it!

 

[gladehound]

Proper counter weighting will allow you to break your loader frame before your front axle ever gives up, and that probably only happens if "bulldozing" where you can apply more force to the loader than it was designed for.

Hmmm... which costs more to fix? I think I'd rather break the loader. A local welding shop should be able to fix that fairly easily and cheaply.

 

[sd455dan]

You must never have been on a teeter-totter. You couldn't possible think the way you do if you had. A tractor with FEL and rear ballast (behind the rear wheel) will act the same way. Just because the wheels are all on the ground, it doesn't mean that they continue to have the same force exerted on them as weight is added at either end. I have seen my fathers old 8N with all four tires on the ground but with such light force that turning the steering wheel had no effect on turning the tractor. By your thoughts, as long as all 4 wheels are on the ground adding weight to either end has no effect. You can put enough weight on either end that the tires are on the ground, but a 6 year old could lift the light end off the ground.
I just find it hard to believe that folks cant understand simple weight and balance problems when it comes to tractors.

Well not to hammer on Axle hub but- has gone around with some other posters on this issue before- including me.
He was able to dismount his tractor, (FEL loaded) and have a rear tire loose contact with the ground in an earlier thread-
but at that time apparently did not think adding substantial weight to the 3 point would be of much benefit...
Hope it has been made much clearer - some weight added to or behind the 3 point most certainly helps when hauling a lot of weight in the FELs bucket
And has a lot to do with safe tractor operation.
This has been made clear with posts on this and other threads.
Thought this and many previous threads settled it -but in the future will see another thread, or some will keep disputing well Known facts...

my:2cents:

ps
after reading the above posts (The other side of the coin) I admit adding weight to the rear of the tractor and heavy fel loading while roughly operating the machine has led to breaking a machine or two in half. Finding a happy medium with safe operation is what everyone shoots for.

 

[Snowback]

Not calling anyone out because I have valued and enjoyed all of this discussion, but I do encourage some thought on this if you are still struggling. I noticed something here that a few folks are missing and it is critical.

When one loads a loader, or forks, or a grapple - that weight/force is not being placed directly in front of the axle like in the case of a snow plow on a truck. The loader connection points to the tractor are typically located closer to the operator station and thus the forces are distributed to both the rear and front axles through the tractor frame. It is the distance to fulcrum where the force acts that is important here. One can still load the bucket sufficiently to "unload" the unweighted rear, but point is you are not placing and distributing the force directly at and beyond the front of the front axle.

This concept allows fun center of gravity toys like this to function.

So - adding 1,000 pounds on your 3pt can easily and fully counter balance a full 1,000+ pounds in your loader due to where the forces are actually acting. In this case your loader force is always acting behind your front axle, and if the load is extended far enough forward, or heavy enough to push the center of gravity past the front axle, then it will tip up. (That would be the case where someone pushed down on the eagles wings and your finger is the center of gravity/front axle).

That tipping forward will never happen if you have proper counter balance beyond the rear axle, AND your operating front axle loads will be at or below a fully unloaded tractor scenario. Having counterweights protrude past the rear wheels is a little bit of a pain for agility, but placing just 500-1,000+ pounds a good distance outward of the rear axle will let you do wheelies all day with a completely full loader and a football team hanging off the loader. This is why I sometimes use a heavy duty cutter for counter weight as it places some of the weight at a greater distance and provides a greater force/moment acting on the rear axle fulcrum which in turn helps reduce the loading on the front axle in all circumstances.

To help with the wheels on ground vs lifted issue, think about the split second before your rear wheels lift off the ground. At the point, all four tires are still in contact and yet the force on your front axle is almost at its maximum stress. If you placed your pinkie finger on the loader bucket and pressed down, then the rear wheels would lift off the ground. The difference in force on front axle in those two scenarios is negligible. The force progression is continuous and nothing special happens when the rear wheels finally come off the ground. The force on the rear axle simply goes from one pound to zero pounds...

Conclusions:

1) Counter balance weight at almost any distance behind the rear axle can and will offset similar weights/forces added to the frame of the tractor and thereby front axle when using a loader. More weight, and or greater distance from the rear axle will amplify the effects of lightening the front axle load. The impacts are far greater than just a nominal 10% or so mentioned earlier since the loader is imparting its forces towards the middle of the tractor which is not too terribly much farther from the rear axle than are the ends of your three point hitch and added counter weights. (Box Blade, Cutter, etc...)

2) Center of gravity is important to understand as well as fulcrums and force amplifiers. (Distance from fulcrum, etc...) Front end loaders are designed to place the actual working forces as close to the CG as possible, but moving them up or down can change the situation drastically in seconds. This is why counter balance rear of the rear axle is so effective at correcting problems associated with overloaded front axles.

3) Perhaps your front axle might not break of wear out right away if not using proper counter weighting, but it is safer, makes the tractor handle better, and keeps the front axle loaded within its working limits so I would suggest it. (And so as not to be accused of being a hypocrite, I do use my loader without counter weighting from time to time for light work, so shame on me.)

Stay safe everyone!

 

[k0ua]

Well not to hammer on Axle hub but- has gone around with some other posters on this issue before- including me.
He was able to dismount his tractor, (FEL loaded) and have a rear tire loose contact with the ground in an earlier thread-
but at that time apparently did not think adding substantial weight to the 3 point would be of much benefit...
Hope it has been made much clearer - some weight added to or behind the 3 point most certainly helps when hauling a lot of weight in the FELs bucket
And has a lot to do with safe tractor operation.
This has been made clear with posts on this and other threads.
Thought this and many previous threads settled it -but in the future will see another thread, or some will keep disputing well Known facts...

my:2cents:

Along that same line I will "fess up" to an almost disaster that happened to me on the last day I owned my Kubota L3400. I had picked up a rock that was at the limits of the loader. I don't know how much it weighed, but it was a big one. I was getting to place it into position on the rock wall the wife and I were building, when she said it would not fit, and she needed help from me with the bar to move another rock to make room for this one.

So I needed to dismount the tractor, and since I had quite a bit of trouble lifting this huge rock, I was reluctant to drop it back on the ground. I kept it up about a foot off of the ground, and set the parking brakes, and thought I had better drop my 3pt ballast, at that time about 750 lbs to the ground to also act as an anchor.

It turns out that dropping the 3pt ballast to the ground was not such a good idea, as when I dismounted the tractor on the slightly downhill side (the left) the tractor started to overturn. My weight in the seat was the only thing holding the rear on the ground after I dropped the 3pt counterbalance to the ground.

I was already on the ground as the slow roll of the tractor around the front axle pivot continued, I held the tractor from rolling over while the wife ran around to the other side and dropped the FEL load to the ground. Whew!, Disaster averted, but If I had kept the 3pt ballast up this would have never happened.

The 3pt ballast made all the difference in the world of planting those rear tires on the ground or letting them come up and allowing the roll around the axis of the front axle pivot bolt. Lesson learned. Oh by the way, the rear tires were also loaded with fluid, but still the high side rear tire was off of the ground over a foot. The sidehill angle was very slight, not much of an angle at all but it was enough when there is not enough weight on the rear to keep both rear tires planted.

 

[zzvyb6]

I must admit, this discussion has been quite amusing to me because of all the theories and opinions expressed. I am a professional engineer, but will only make 4 comments:

1) The toy tractor on an egg scale is the best science project and analysis that has been submitted to this thread. This 'scaled' demonstration is frequently done for many, many, many such industry discussions. 1/4 scale models for wind tunnel measurements of racing cars is an example. This was a breath of fresh air from the list of stagnant, tired and wrong arguments.

2) My thoughts on this are: Loader work is really hard on tires and wheels because of the scrub while turning. And this is the main reason to have a ballast box. Tire wear goes up as the cube of load on them. Adding front air pressure is very important to maintain when heavy loads are carried by the loader. Even wheel fracture is possible as well as tire de-beading. Rear wheel spin is also a problem for tire wear. However, when using the tractor with loader, and 4 wheel drive, there can be large loads on the transmission because of the mismatch now between designed-for wheel rpm ratio. Some of you may find that its hard to change gears because of this internal loading. That's why 4 wheel assist is a benefit to loader work. The driveline strains are not as large. 4wheel assist is electric or hydraulic motor traction instead of direct shaft drive.

3) I doubt that a good , modern tractor designer has ignored potential foreseeable misuse (as its called in the trade) so there is plenty of reserve margin for axle housing size, weight, bearings, seals and fasteners. Tires and wheels, too. But I said a GOOD design, not a homeowner design where a loader is to be used to carry out the garbage cans every Tuesday.

4) The 'Math' behind all of this jaw boning would be taking Moments (force times distance) from any convenient single point in the side view and summing them up. Same analysis used to figure out where a previous threadster's trailer axle needed to be in order to reduce his tongue load. Yes, you need to include the tractor's wheel weights, center of gravity and total weight, loader content weight, ballast box weight and the distances from each point mass to the chosen central moment point. Then its just sophmore High School algebra.

 

[sd455dan]

Wow James that sounds like a hair raising experience! So the 3 point ballast would not have kept the rotation of the tractor around the front axle pivot from continuing?
Would have thought the 3 point arms/top link would at least keep the tractor from going over- unless it was to flip also?


I can't say that 3 point weight has not caused problems for me either...
One time trying to push dirt back with the Gannon boxblade the force caused an old weld to break on the left 3 point arm mount.
The left rear tire (14.9x 28) backed over the gannon and went up in the air (wife said 2 feet!) before I could get the clutch pushed in and slammed me into the ROPS ringing my bell pretty good.
Luckily No front axle damage was done :laughing: can't say the same for the mount on the Gannon and my pride,we all make mistakes and stuff does happen, hopefully we all learn from mistakes and experience.