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

[jenkinsph]

If you lift 1000 pounds with the FEL your adding a 1000 pounds to the front axle regardless how much weight you have on the rear.

Ballast on the rear helps with keeping the rear tires in contact with the ground but it doesn't take any load off of the front axle.

Curious whether you read this thread or did you post without reading it?

 

[aczlan]

If you lift 1000 pounds with the FEL your adding a 1000 pounds to the front axle regardless how much weight you have on the rear.
Ballast on the rear helps with keeping the rear tires in contact with the ground but it doesn't take any load off of the front axle.

If you are just talking about weight on/in the tires (ie: wheel weights or loaded tires), you are correct.
If you are including 3 point counterweights, you are incorrect and you need to read the thread (especially the examples showing a toy tractor on a scale).

Aaron Z

 

[k0ua]

If you lift 1000 pounds with the FEL your adding a 1000 pounds to the front axle regardless how much weight you have on the rear.

Ballast on the rear helps with keeping the rear tires in contact with the ground but it doesn't take any load off of the front axle.

And the earth is flat, correct?

 

[LD1]

Curious whether you read this thread or did you post without reading it?

Was wondering the same thing.

If you lift 1000 pounds with the FEL your adding a 1000 pounds to the front axle regardless how much weight you have on the rear.

Ballast on the rear helps with keeping the rear tires in contact with the ground but it doesn't take any load off of the front axle.

Wrong no both accounts.

First, if you add 1000# to the FEL, you are adding MORE than 1000# to the front axle. You would be adding 1000# + whatever weight is transferred off the rear axle. How much that gets transferred depends on loader design. (Moment arm length)

Second, and has been said more times than I can count in this thread alone, weight behind the rear axle DOES take weight off the front axle. No if by ballast you had it stuck in your head that we were only talking about wheel weights and/or loaded tires then you are correct, that wont unload the front axle. But for the sake of this thread, the ballast we have been talking about is a ballast attached to a 3PH behind the rear axle, and that most certainly takes weight off the front axle.

 

[sd455dan]

This reminds me of a fire, every time you think you finally have it put out - it starts up in another place!:laughing:

 

[LD1]

This reminds me of a fire, every time you think you finally have it put out - it starts up in another place!:laughing:

Aint that the truth.

I dont see what is so hard about the concept. Its a pretty freaking simple lever.

Everone wants to try to make things like the parallelogram and very dynamic 3PH and the arc of a FEL lift into a simple lever.

Yet when actually presented with a simple lever, everyone wants to WAY over complicate it

 

[Snowback]

I think Old Pilgrim's point is that moving the loaded loader CG from in front of the front axle closer to the actual front axle by lifting it up higher will indeed help put some of the weight back on the rear axle. It would simply be the weight that was lifted off the rear during the initial loading when load CG was extended out past the front of the front axle. In doing this, (raising the loader), he was able to move his loader's CG backwards and get enough traction on the rear wheels again to back up the hill. It was not loader force transfering the weight to the back as much as it was the loader putting some of the weight back that it had originally taken off. Even if that was not his point, it is a point that we have all pointed out now a few dozen times. I acknowledge that I muddied the water as I was not clear about differentiating between the net CG effects and the physical path of the forces getting from the "load" through the loader arms and back through the frame to the front axle. It reads very poorly when I go back and look at my post again. In reality that is only important when understanding the potential failure mechanisms in our machines. My apologies for that. These discussions should probably just stick to free body diagrams like were presented in an earlier thread link and scale model tests which are really useful. The simple ones don't perfectly account for the vertical effects and impacts on moments when shifting load up and down, but they're still really useful.

So quick question: Who has even had sufficient counter balance weighting to do this when in a fully raised position when backing up? The video can be found at this link here: https://www.youtube.com/watch?v=6WHrXlgGnSs

Also - these guys have some CG balancing skills! https://www.youtube.com/watch?v=6bg...Qzx917eUkVk-aGdnCNgWs8vGB0MgJTwUsa4gheD_1KS9A

Stay safe all!

 

[SPYDERLK]

Yeah it was crawling up hill on its front tires, with the entire tractor weight, the ballast weight, and what ever that big ole rock weighed. All on the front axle. It is a wonder something didn't go POP.

From support of weight alone this is true. When backing up tho your abusive situation is limited in a couple ways: 1] directional tread does not grip as well, and 2] front overbalance occurs easily because drive tries to rotate the tractor onto its nose, touches down the load and decreases the supported weight and traction. -- Drive torque is thus limited.

,,,Going forward presents a situation that can easily cause more abuse to the front axle and drive. ... Of course the directional tread gives more traction so more torque can be transmitted. ... But, building on this is the greater stability of the tractor/loader assembly for lifting and pushing. - Lift/curl while pushing at ground level will elevate a load that the loader is unable to lift, and that the physics of the platform is not able to hold up except while pushing. Platform balance and drive countertorque on the chassis add to cause the load to come up. Every time you decelerate or stop the bucket goes back down and the back wheels come up. Start forward again and the tractor climbs under the load. Usually the back wheels touch down and "some steering" is possible, but in essence all weight/traction/drive is on the front. ... The entire weight of the platform and more than the loader will lift. When 4wd tractors are built without an eye for this case you start seeing the drive and axle housing failures.

 

[k0ua]

From support of weight alone this is true. When backing up tho your abusive situation is limited in a couple ways: 1] directional tread does not grip as well, and 2] front overbalance occurs easily because drive tries to rotate the tractor onto its nose, touches down the load and decreases the supported weight and traction. -- Drive torque is thus limited.

,,,Going forward presents a situation that can easily cause more abuse to the front axle and drive. ... Of course the directional tread gives more traction so more torque can be transmitted. ... But, building on this is the greater stability of the tractor/loader assembly for lifting and pushing. - Lift/curl while pushing at ground level will elevate a load that the loader is unable to lift, and that the physics of the platform is not able to hold up except while pushing. Platform balance and drive countertorque on the chassis add to cause the load to come up. Every time you decelerate or stop the bucket goes back down and the back wheels come up. Start forward again and the tractor climbs under the load. Usually the back wheels touch down and "some steering" is possible, but in essence all weight/traction/drive is on the front. ... The entire weight of the platform and more than the loader will lift. When 4wd tractors are built without an eye for this case you start seeing the drive and axle housing failures.

Well, it seemed that Kubota builds a tough enough axle to survive the abuse I heaped on it that day. Nothing broke. Interestingly my Kioti axles are larger still. But I have learned a few things since that day, I take things a little easier, and try to work safer.

 

[GolfAddict]

If you lift 1000 pounds with the FEL your adding a 1000 pounds to the front axle regardless how much weight you have on the rear.

Ballast on the rear helps with keeping the rear tires in contact with the ground but it doesn't take any load off of the front axle.

If you haven't read the whole thread yet, keep reading. Once you get to where you see tire squishing comes in to play it will all become clear.

 

[oldpilgrim]

It was not loader force transfering the weight to the back as much as it was the loader putting some of the weight back that it had originally taken off.

This is a fine example of the semantics I was referring to. If you put back weight that 'had been taken off', you are adding weight where there isn't weight. I've never said that you are 'removing' weight, this whole discussion is about weight transfer. We're discussing a fixed weight tractor with a fixed load. Moving the lift point or moving the load to various positions will 'put back' or 'remove' weight from one point or another.

Maybe I just don't know how to talk the language of physics.

 

[gladehound]

So quick question: Who has even had sufficient counter balance weighting to do this when in a fully raised position when backing up? The video can be found at this link here: https://www.youtube.com/watch?v=6WHrXlgGnSs
View attachment 458519

Stay safe all!

That was more momentum that counter weight.

 

[kevin37b]

Probably more alcohol , him and her than brains .

 

[DavesTractor]

So now getting back on topic - this thread was never supposed to be about the physics of ballast. I actually assumed that everyone was on the same page with the general principles.

I still want to know if anyone has actually "trashed" a front axle, or had premature wear issues, from running too little ballast on the 3pt?

We have one broken axle example so far but that sounds like ballast on the 3pt might not help if you decide to wedge the front end between the earth and a tree trunk and keep driving forward.

(That example would actually be fun to talk about in terms of physics because I can see how several multiples of the tractor's actual weight could be applied to the front axle.)

The real issue is that our tractors are front wheel assist, not true 4wd. The front axle shafts and ring and pinion are meant to only assist in propelling the tractor along the ground. If you lack adequate ballast and the rear tires are essentially in the air, and you push hard or perhaps back up a steep slope with a full bucket and the front axle doing all the work, that is when you snap an axle shaft or strip the ring gear or pinion. It is designed for a load of X and we are asking it to do 4X. Having adequate ballast helps keep the rear tires in the mix all the time for tractive force. The rear ring gear and pinion and shafts are much more robust.

Guys will break front axle shafts and gears, and we can tell them what they were doing when it broke. They were in some manner putting a huge load on the front axle, the front axle had superb traction, and they were trying to move the tractor in a extremely high load situation.

Example 1: Put the bucket under a stubborn stump, lift with the bucket until the back end is pretty much off the ground, now hammer forward and see what happens. Here are the options: 1) The stump gives way. 2) The engine dies. 3) The clutch slips. 4) The front tires spin. 5) Something breaks. No other options. And we have a lot of torque with our low gearing, so the engine generally won't die, clutches generally do not let go with low gearing, the front tires have maximum traction. Pop goes the ring gear, or if you are lucky, just a shaft. Now I'll admit that rear ballast doesn't solve "stupid", but it does help in many situations....but probably not in this stump scenario.

Example 2: Backing up a steep creek bank or pond bank with a fully loaded bucket and the rear tires essentially out of the mix. A full size commercial machine or a wheel loader can do this all day long. A CUT is somewhat at risk. Although this is a better scenario then the "stump" as there is still a chance that the front tires will spin before you have breakage. A gentle operator can do this with a CUT, but it does put a bunch of load on the front axle gears/shafts. In this scenario, rear ballast will definitely help save the front axle from gear/shaft damage.

I hope this was helpful. If we understand how and why things break, we tend to break things less often.

 

[oldpilgrim]

jokingly, a ways back, I said if you loaded the bucket enough the front wheels would come up...and you guys thought I was nutz !!!!!

 

[Snowback]

A gentle operator can do this with a CUT, but it does put a bunch of load on the front axle gears/shafts. In this scenario, rear ballast will definitely help save the front axle from gear/shaft damage.

Thanks Dave - good to hear a Dealer opinion too. Per your comment above - do you mean like this kind of gentle operator? (Sorry Ted - I had to do it...)

I love the EA Wicked Grapples and I really enjoy watching Ted put these things through their paces. This is actually a good advertisement for Kubota as well!

**** Don't do this at home! **** Full video of the grapple work and testing here: https://www.youtube.com/watch?v=w-2UB9k86BA

 

[SPYDERLK]

Thanks Dave - good to hear a Dealer opinion too. Per your comment above - do you mean like this kind of gentle operator? (Sorry Ted - I had to do it...)

View attachment 458538

I love the EA Wicked Grapples and I really enjoy watching Ted put these things through their paces. This is actually a good advertisement for Kubota as well!

**** Don't do this at home! **** Full video of the grapple work and testing here: https://www.youtube.com/watch?v=w-2UB9k86BA

Yeah, that happens to me on the 7520 too. You cant generate much force in reverse cuz you get "out of shape" too easy from a pull point in the bucket. It is the time to crunch the load forward abit to break it free.

 

[DavesTractor]

Thanks Dave - good to hear a Dealer opinion too. Per your comment above - do you mean like this kind of gentle operator? (Sorry Ted - I had to do it...)

View attachment 458538

I love the EA Wicked Grapples and I really enjoy watching Ted put these things through their paces. This is actually a good advertisement for Kubota as well!

**** Don't do this at home! **** Full video of the grapple work and testing here: https://www.youtube.com/watch?v=w-2UB9k86BA

Oh yeah! That's the sort of gentle we hear about after an axle broke. I always wished we had a picture! That looks a little scary.

The first time I almost rolled a tractor was using forks and lifting a pallet of comp. shingles off a flatbed. I carefully tested and it lifted it and the rear tires were not showing air beneath them. I slowly backed away from the truck, then made the mistake of turning sharply while backing. That moved the centerline of one front tire contact patch back an inch or two and I started going over. I slammed the loader down and kept from rolling over, but it taught me a lesson. Now if I am feeling stupid like that, I'll lift the load, then drive the truck out, then lower the load. But then again I once got off the tractor to move the truck, and my svelte 225lbs missing from the seat caused the back tires to come up. I was simply ballast, and not much smarter than the average ballast at that point!

 

[Snowback]

Beating a dead horse, but might help newcomers understand why the counterbalance is desirable. Just another observation for purists who do a lot of loader work. Skidsteers are almost exclusively loader machines, and they seem to have a lot of built in counterweight behind the rear axle as well. Some more than others as below! (Even with a bucket this would be strongly rear weighted for maximum loader capacity.)

Full video here: https://www.youtube.com/watch?v=SvRDr8s7Lmc

 

[5030]

Well, after reading this entire and somewhat convoluted thread, I've come to the conclusion that tiny tractors lack the meat in the front axle assembly to withstand much abuse.

Having said that I regularly haul single 4 x 6 round bales (about 1200 pounds each, across hay fields and load on trucks. I prefer one on the back spear and one or two on the front spears but oftentimes thats not doable. I've never had issue one with either of my FWA Kubota tractors which leads me to believe the large frame units are plenty robust enough to take the weight on the front axle..;.... and I'm rarely in FWA anyway. Most times, I'm in 2wd, but then both of my tractors I ordered with cast wheel weights. I'm not a believer in loading tires with any liquid on a FWA unit. Even when performing tillage operations, I experience very little wheel slippage.

Additionally, I'd never loft my rear wheels in any situation. With no suspension at all. it don't take much loft to roll a tractor. My balls aren't that large and my brain is obviously larger.