4WD variations.?

[Schneeky]

.. I don't mean to hog the forum.. Hopefully someone else has the same questions that need answering..

.. Seems like I've heard or read somewhere that there's different kinds of 4WD available on tractors.. I know I've heard of a "forward assist" or some such.. Then there's that funky little thing on the Kubota's that knocks out the 4WD in tight turns..
.. What all kindof 4WD variations are there and are any of them to be avoided.? Thanks.!! d:^) Schneeky..

 

[Bob_Young]

This thread should bring some interesting information out of the woodwork.

In terms of design, I know there's the fully enclosed bevel gear drive system used by Kubota and the half-shaft from a central differential design used by everyone (?) else. The bevel gear system works really well...on small tractors at least. I have seen a few posts saying it's not the best choice for really large tractors and not as strong as the half-shaft designs. What they may really be saying is that the bevel gear front axles are more expensive for a given level of strength and, beyond a certain point, become cost prohibitive.

Don't know of anything on a Kubota that knocks out 4WD on a tight turn. Never seen it work that way on my own tractors; though I try to avoid turning tight while in 4WD.
Bob

 

[piller]

Kubota likes to point out that their enclosed bevel gear front axle drive systems deliver full power at all steering angles.

 

[roxynoodle]

My understanding is that all compact tractors use "front wheel assist" rather than true 4wd. At least I haven't seen a compact with true 4wd. A true 4wd will have the same size front tires as rear tires, like the Steigers do. We use the term "4wd" loosely to mean we can engage the front as well as the back.

 

[ericher69]

My understanding is that all compact tractors use "front wheel assist" rather than true 4wd. At least I haven't seen a compact with true 4wd. A true 4wd will have the same size front tires as rear tires, like the Steigers do. We use the term "4wd" loosely to mean we can engage the front as well as the back.

Not so! Tires can be different sizes and still be a "true" 4wd as long as it is geared properly.

 

[slewisma]

Not so! Tires can be different sizes and still be a "true" 4wd as long as it is geared properly.

The contact patch on those little front tires is a lot smaller than on the rears. So, if geared right, you can have full 4WD on anything but how much additional traction you'll experience is a separate question.

I can't speak for CUTs since I have a BX-24. I can say that on SCUTs, those front tires can sink the front to the frame in less time than it takes to realize you are getting stuck.

4WD is a very valuable feature for having four wheel braking through HST and it will probably be of some help in the winter on the driveway. In deep mud, not so helpful.

 

[IslandTractor]

Kubota likes to point out that their enclosed bevel gear front axle drive systems deliver full power at all steering angles.

What is the big deal about full power at all steering angles with a tractor? Full power and traction is typically needed when pulling a plow which is generally in a straight line or when loading the FEL bucket which is also a straightahead direction. When do you need full power/traction while turning hard with a tractor?

Seems to me this is just a marketing gimick.

 

[Schneeky]

..Hey IT, what do ya call that contraption on yer FEL there.? Looks like somethin I'd be interested in..
Will it go in place of a regular bucket or are there some additional hydraulics needed.? Thanks..

..Look Gizmo.. It's starting already.. Dang.!! d:^) Schneeky..

 

[IslandTractor]

..Hey IT, what do ya call that contraption on yer FEL there.? Looks like somethin I'd be interested in..
Will it go in place of a regular bucket or are there some additional hydraulics needed.? Thanks..

..Look Gizmo.. It's starting already.. Dang.!! d:^) Schneeky..

It is a grapple. do a search and you will find hours of reading on the subject here on TBN.

Yes, you would need to run hydraulics to the grapple. Several options. Again, do a search on diverter valve or rear remote and grapple. There is lots of info here on TBN on these subjects.

 

[stevem5215]

I have a Steiner 4wd Hydro tractor and it's a true system of 4wd. You can have wheel(s) in the air and they still only turn as fast as the ones on the ground. It's one h*ll of a machine for snow removal with the mini bucket (4ft) on it. I've never seen a tractor that can push a 3 foot pile of snow in front of the bucket UP a hill around a bend and pushing it in the direction you want to go. It's unbelieveable awesome. Also, this past winter I was plowing with it and went to take the trash can up the hill. It turned out there was ice under the snow and I could barely stand on the driveway on the slope. But it was weird that the Steiner could clear that snow without issues where I couldn't even walk. Just goes to show when engineering is applied to a solution what can be done.

Steve
Ford 1900 4wd & Steiner 420