For those of you who think the L3400 has a weak loader!!

[xring100]

k0ua
I see this: how are you planning on picking up 5000# on a tractor(L3400) that will only supposedly pick up 1985#s even with end of the 3 pt draft links? No one is going to have counterbalance weights to "your extremes". Here's what I'll do Tuesday, I'll take my M7040 with FEL to a certified scale. I'll weight frt axle with a rd bale on FEL no counterbalance weight then weight frt axle with bale of hay on frt & rear and report back. Well see how much difference in the ACTUAL WEIGHTS

.I believe in correct information on a discussion forum

To see the weight transfer in action
Put the heaviest longest object you can on the 3pt and the most amount of weight you can on the FEL. Start with both in contact with the ground. Now lift the 3 pt and watch the rear tires squat as all this weight is shifted on to the rears. You will also notice the front tires rise off the ground some. Now lift the FEL off the ground and observe the rear axle raise back off the ground some and the rear tires are not squatting so much but the front tires are now squatting.

Next lower the 3 pt to the ground the rear tires squat even less if the FEL has enough load the rear tires will be off the ground and 100% of the load will be on the front axle and squatting like crazy, the tires might look like there going flat or about to explode. Raising the 3pt again will again return load on the rear axle and shift weight off the front axle and onto the rear.
I see this regularly although not to the same level I'm suggesting my loader weighs about 2500 lbs with empty bucket although only part of this weight is transfered to the ground through the bucket. my carry all box weighs north of 1600 lbs fully loaded with wood. I usually pull into my barn leave the bucket and 3 pt up. I Idle down to let the turbonium spool down/ cool down. Set park brake dismount the tractor. I then Ensure the tractor is far enough in to close the barn door. Then i close and lock barn door if far enough in. I then walk around to the side of the tractor with loader and 3pt controls and shutoff the tractor. then i drop the 3pt, while simultaneously observing the rear lift and front squat. Then i lower the loader and relieve all residual pressure. At startup i lift the bucket first.

As an alternate You could draw free body diagrams with assumed cg locations and weights and calculate the weight transfer without going to the scales. Relatively simple statics problem although i'd probably have to pull out one of my old college text books for a refresher its been over 10 years since I've solved this type of problem . On second thought if the scales are close this is probably faster

 

[LD1]

Been busy for the last few days tearing down a barn and doing a tiling job. So thanks everyone for jumping in and helping explain the point. I dont think I could have done it any better.

I would dearly love to see your theory of relieving weight off front axle by adding weight behind rear axle confirmed by use of platform scales to weight frt axle load. I understand Fulcrum effect but doubt seriously that will lessen stress on frt axle.

k0ua
I see this: how are you planning on picking up 5000# on a tractor(L3400) that will only supposedly pick up 1985#s even with end of the 3 pt draft links? No one is going to have counterbalance weights to "your extremes". Here's what I'll do Tuesday, I'll take my M7040 with FEL to a certified scale. I'll weight frt axle with a rd bale on FEL no counterbalance weight then weight frt axle with bale of hay on frt & rear and report back. Well see how much difference in the ACTUAL WEIGHTS

.I believe in correct information on a discussion forum

Jim, its simple physics. Any weight added behind the rear axle (provided it stays in contact with the ground) will shift weight OFF of the front. How much is just a matter of a few measurements. Wheelbase and how far the load sticks out back for starters.

It really is the same thing as when you lift a load with the loader and you can see/feel the rear get light. Well, when you have a load on the back, the reverse is true, the fronts get light. How much just depends on the geometry of the tractor. I am very much looking forward to your real world results. If I had access to scales, I would love to give a demo, but I dont have access.

 

[repete]

Under normal circumstances putting the cg height of the mass higher in the air only results in the tractor being more unstable and prone to tip. It is best to keep the center of mass below the rears tires. If you were to draw a free body diagram in various operating angles you would find the main factor at play is how far behind the tires the center of mass is located. With a high 3pt mass you would find going down hill the tractor would be more likely to tip forward. Going up hill it would be more likely to wheelie on you. This is the same reason your loaders operators manual probably makes multiple recurrences to carrying the load in the bucket a close to the ground as possible.

While the tension load will increase on the top link as you shift the weight back farther behind the tractor its still ultimately the lower links that provide the support force and carry the weight. This does not really come into play If the same amount of weight at the same cg height and distance behind the rear axle was attached via the draw bar instead of the 3 pt the handling characteristic would be the same the load on the upper link does not matter in this case because it was eliminated.

If i take my 1400 lb 10 ft long brush hog and lift it 3" off the ground or 3 feet off the ground you will see virtually no difference in weight on the front axle on a level grade
( assuming the rear tail wheel is not in contact with the ground in either condition.) There will be some change as the 3pt is raised, as the arms travel through An arc. the distance of the rear pivot pins behind the axle will be the greatest when the lower links are level.

Keep it low keep it stable

Agreed on keeping the CoG as low as possible. I have some steep hillsides and learned that years ago. Always when on a slope with a loaded bucket keep the hand on the lever and if you feel it rolling drop the bucket as fast as possible.

As for the weight, I was considering the use of a hand truck to lift a refer. If I grab the hand truck and pull back at the bottom it is not as easy to tilt the refer as if I had lifted the hand truck at the top. I was making the projection that if I had the weight pulling on the top link it may have the same effect. Keep the weight low, but place as much of the load as possible pulling back on the top link.

 

[Tx Jim]

RaydaKub
Actually the scales I'm planning to use is a BTO that raises crops,cattle & sells fert/seed that I buy my fert. from. I think they will let me weigh several different configurations. I was curious what my newly acquired M7040/LA153SA weights anyway.

 

[LD1]

RaydaKub
Actually the scales I'm planning to use is a BTO that raises crops,cattle & sells fert/seed that I buy my fert. from. I think they will let me weigh several different configurations. I was curious what my newly acquired M7040/LA153SA weights anyway.

Certainly looking forward to it.

It WILL reduce the weight over the front, but how much, I guess we'll find out. Given the wheelbase and what-not, I am guessing that it will unload the front by half of whatever the bale weighs.

IE: if the bales weighs 1000lbs, I am guessing that you will see a 500# or so reduction up front. Which in turn will add another 1500 to the rear (1000 for the bale and 500 taken from the front)

Which kinda leads to another point.....When doing heavy loader work and pushing into piles, better to keep the weight over your bigger tires for traction. ESPECIALLY if you have a 2wd tractor.

 

[Tx Jim]

LD1
As I previously stated I think rear weight won't """significantly reduce the weight exerted on frt axle""" especially to the 50% amount you're thinking. But the proof will be in weighing!!!!!!!!

 

[Bluegill2]

LD1
As I previously stated I think rear weight won't """significantly reduce the weight exerted on frt axle""" especially to the 50% amount you're thinking. But the proof will be in weighing!!!!!!!!

I'm thinking around 25-30% on that size rig with said weight.

For the size of your tractor, I think it will take more than 1000 lbs to get to 50%.

But with enough weight on the rear, 100% of the weight could be taken off the front axle.

 

[k0ua]

But with enough weight on the rear, 100% of the weight could be taken off the front axle.

Exactly, and that was my point about using the absurdly high values of weight on the rear. If you put enough on the rear it would raise the front wheels off of the ground. Another way to look at this is to put a 20 foot long boom pole on the 3pt. now put about 500 lbs on the end of the boom pole... front wheels off of the ground. :shocked:

 

[Bluegill2]

Exactly, and that was my point about using the absurdly high values of weight on the rear. If you put enough on the rear it would raise the front wheels off of the ground. Another way to look at this is to put a 20 foot long boom pole on the 3pt. now put about 500 lbs on the end of the boom pole... front wheels off of the ground. :shocked:

Yes, it is pretty simple.

But I'm thinking with a L7040 and 1000 lb round bales, the weight difference wont be that dramatic.

1000lbs is just about perfect for rear ballast on my L3800. You can see the front come up when that rear weight is lifted.

 

[case245]

txjim my 7040sud with 1153 fel cast centers loaded rears its a little over 8000ibs