Newby question on correct use of the FEL

[flusher]

I was reading a recent post in

HELP PLEASE! I need Serious Help!

One of the participants noted that you can tear up the front end while in 4WD by continuing to push into a pile of dirt or whatever when the front wheels stop turning. The spider gears could fail in this situation according to that posting.

When the dealer delivered my Kubota B7510HST last June, he recommended that I put the tranny in 4WD and keep it there. Since then I've been using the FEL in 4WD to move sand and gravel around, scrape a few inches of turf off areas where I plan to build small sheds and to level out the excavated dirt piles around my house construction site.

Lately I've noticed that I've gotten into the habit of lifting the front wheels a few inches off ground with the loader when pushing the bucket into a pile of dirt or gravel, letting the rear wheels do the work while rotating and lifting the bucket to take the bite.

Question: is this the correct, proper, recommended (you take your pick) way to do this maneuver? Seems to me that doing it this way eliminates any chance of busting the front wheel drive mechanism. But does this put extra strain on the FEL arms and hydraulics that will cause me problems in the future?

Newy asks for advice and is grateful for any and all help.

 

[BadDog]

2 'rules' are important in my opinion:

1) If you are in 4WD you need to be on a surface that will allow your front wheels to slip when you turn a corner in the tractor. Loose Gravel, loose soil, sand, grass (especially wet) should all be OK. Pavement, tightly packed gravel, sand or soil are not OK. This is true regardless of whether you are using the FEL or not.

2) You need enough counterweight (rear wheel weights or filled tires, a rear implement attached, or a combination of any/all) to make sure you always have enough weight on the rear end to:
a) keep it firmly on the ground and;
b) let it provide power to move the tractor.

If your back end ever comes off the ground with a full FEL, then your front end is going to handle all the stress of the entire tractor + it's load + moving the tractor + steering the tractor. That is just too much to ask of it. It might do it for a while, but it just won't last.

In the case you describe, where you're leaving the tractor in 4WD while lifting the front wheels off the ground to push into a pile of material, you are probably violating rule #1 above. I worry that when you drop the front end back down you are doing it with the tractor still in gear, and jarring the moving front end in the process. This is bad because:

a) you have just compacted the ground under the front wheels by pushing the tractor bucket across it with the front wheels off the ground. It sounds like you are likely repeating this over and over, further compacting the ground. This makes it very unlikely that the front wheels can spin enough when they hit the ground in motion, unless you have bald tires. /forums/images/graemlins/wink.gif They are likely to be spinning somewhat and then be forced to a full stop when they hit the ground. You are effectively using a really big sledgehammer on the gears in your front end. Not good.
b) You are doing this with a full FEL load! This makes the sledgehammer even bigger. /forums/images/graemlins/shocked.gif

My advice is:
a) get some serious counterweight, and;
b) use 2WD when doing lots of heavy FEL work.

If you are in 2WD and have enough counterweight, you should be able to use your FEL just as, and maybe even more effectively than when in 4WD. I put my backhoe on when I'm doing any serious FEL work and use 2WD only, unless I get myself really stuck. Note that my tires are filled w/ CaCL, I have 400 lbs of rear wheel weights, and the backhoe weighs around 1500 lbs with the heavy duty bucket mounted. My rig feels like a bulldozer all loaded up and there is no better feeling than demolishing a huge pile of soil with it.

You *should* be able to leave your tractor in 4WD all the time if you don't violate rule #1 and 2 above. After blowing 2 front ends, I've learned the rules the hard way. I hope I can save you the same trouble.

 

[RonR]

I've not torn up front ends like BadDog and I have fewer hours, but here is what I do.

If the wheels can't slip, like on concrete or hard packed dirt, I don't use 4WD. The exception to this is when I need to dig into the ground. Then I use 4WD and keep the front on the ground to pull.

A lot of time, if I dig using 4WD and have to drive over hard pack to dump it, I shift out of 4WD.

I also pay attention to what I'm up against. I don't run the fel into a large tree in either gear and expect it to power through it.

My FEL manual also shows how to dig with it to be most efficient. I have not found any flaws in what they recommend.

I expect my 4WD to outlive me!

Ron

 

[PineRidge]

Flusher I would first recommend to read your operators manual as there is a lot of information there that will be specific to your tractor.

I don't recommend 4WD unless you are working on an area where the wheels can slip. Don't use it on concrete, blacktop, or the like but I'm sure your manual will explain that to you in more detail.

Also when you push into a pile with the FEL curl the bucket while lifting and it will put less strain on your loader.

 

[beenthere]

IMO, and we each see things a bit differently, is you are doing just fine, and the tractor is designed to handle it being in 4wd.

I once was in a meeting with a large group of Deere engineers on the CUT tractors, and this very question was asked. The answer was it is designed to be in 4wd and to handle the 'wind up' difference if there is any. That said, I still shift out of 4wd when not needed on hard asphalt or concrete surface. But when the front wheels are up while doing FEL work, I leave it in 4wd because when I back up with a load, I want the assist from the front wheels to 'help'.

I think too often we have heard the 4wd stories from SUV's and pickups over the years that did have front pumpkin problems caused by stresses when in 4wd. And true, the gray market tractor with the front wheel drive problem is not a pretty picture. Can't tell if it was caused by the FEL work being done, or a weak front end, or a problem prior to purchase of a 're-built' tractor.

So take your pick of responses, but I think you are doing just the way I would do it, and I think your tractor is designed to take the stress. I know mine is, and 'knock on wood' that I don't lose the front end tomorrow. /forums/images/graemlins/tongue.gif

 

[flusher]

BadDog: Thanks for the info.
I use my 48" KK box blade as a counterweight for FEL work. My 10 acre place is grass (weeds, actually) and loose soil.
Only compacted surface is the gravel driveway.
Never have had a need to take the tractor on the road.
I run the tractor/FEL a lot by engine sound and back off the HST throttle when I hear the engine/pump laboring.

 

[flusher]

Thanks for the input.
Checked the Kubota FEL manual (I have an LA302). There's nothing in the "Safe Operation" yellow pages about any cautions when using the FEL in 4WD. In fact, there's nothing about 4WD and FEL interaction in the entire manual.

BTW: There's a warning about connecting chain, cable or rope to the FEL bucket while operating the loader. I don't think this is much of a worry since my Kubota was delivered with chain hooks welded to be bucket by the dealer.

The tractor manual has a 9-page "Safe Operation" section that contains only one reference to 4WD; that in regard to operating the tractor on a slope and being careful when in 4WD not to get a false confidence in the abilty of the tractor to climb the slope.

There is more 4WD info on page 22 where the operation of the 2WD/4WD lever is discussed. According to Kubota 4WD is effective when greater pulling force is needed, e.g. working in a wet field, pulling a trailer, or WHEN WORKING WITH A FRONT-END LOADER.

Kubota also suggest using 4WD when working in sandy soil, when working in hard soil were a rotary tiller might push the tractor forward and for additional braking at reduced speeds.

And that's all Kubota has to say about 4WD and the FEL in their tractor manual.

A newby like myself might interpret this to mean that 4WD is a really good idea when using the FEL. Of course, there're jillions of 2WD tractors with FELs doing just fine.

 

[flusher]

Thanks for your reply.
As a retired aerospace engineer (32 years at McDonnell Douglas), I tend to baby my vehicles and tools. And 4WD systems are not entirely new to me. My introduction to 4WD came in 1982 when I bought a new Subaru wagon (2WD front wheel drive with the 4WD shift between the bucket seats). Got a good education on this type of primitive 4WD setup (primitive compared to today's on-demand 4WD). So I'm always watching and listening for indications that the tractor drive system is jamming up, especially in tight turns.

Nice to know that manufacturers like JD (and the others, I presume) realize that their products must have a certain level of idiot-proofing designed in to keep the less experienced operators, like myself, from generating a lot of warranty repair work. This also reduces the need for operating manuals the size of the telephone directory, although an engineer like myself always wants more information, especially design drawings.

 

[PAexcavator]

I'm on my third Kubota with a loader. I always use 4wd when loading. But it's pointless to select 4wd for extra traction, and then put air under the front axle so it can't generate any.

The instant you lift the front axle you lose a good percentage of available applicable power and are more likely to spin the rears.

The secret to efficient FEL work is to have full buckets. They make jobs go much faster. If your tractor is unstable with a full bucket it doesn't have enough counterweight, add them and/or fill the rear tires.

The other secret of FEL work is learn to use the level gauge on the front bucket to judge the angle of the floor of the bucket. If the angle of bucket is too high, you will feel plenty of resistance, but you will be pushing the material away from the bucket, rather than filling it. If the angle of the bucket is too low, the tractor will usually run out of power from trying to take too big of a bite.

Lay the bucket flat on the ground in front of the pile, and then raise the arms slightly(1"-2") to drive into the pile. Do not crash into the pile. Use low range to get the feel of the "sweet spot" where at the corect angle the bucket slides easily into the pile. This procedure will also keep the front axle on the ground, where it can generate power and spread the load over two axles and differentials.

Do this at SLOW speeds, on HST tractors, your throttle should be at PTO speed, but you only want to barely crack open the foot pedal. Go slow because you want to do three things at once, drive into the pile, slowly curl the bucket, and lift the loader arms. You shouldn't have to spin any tires this way unless your tractor and loader are mismatched.

Most novices think they get more power by pushing harder on the pedal, they are mistaken. You get more speed, but less torque. Torque is what you want more of when pushing anything.

 

[RedRocker]

I'm with PAexcavator, you lose some push with your front wheels in the air. 2WD on concrete and asphalt, 4WD everywhere else. Gravel and dirt will offer plenty of slip for the 4WD.