Another 2wd vs 4wd question

[BethesdaEC]

Not as much as you would think. Because if the driveshaft is being "braked", and one wheel starts to lose its bite, the wheels will be forced to spin opposite directions. And that is unlikely.

We are not sending power. In a differential, there are 3 things. 2 axles and one driveshaft, agreed??

And in an open differential, at any time (except when the tractor is parked), TWO of those three HAVE to be moving. IE: under power it could be the driveshaft and only one wheel moving. BUT under braking, like in a lock-up situation, the driveshaft is NOT turning. Therefor, BOTH wheels either have to be locked UP, Turning the SAME direction, or turning OPPOSITE directions.

IF they are both locked up, they are both applying braking force. IF they are both turning the same direction, they are applying braking force.

Summary of this is, IF one wheel starts to loose traction as you suggest, it has to do more than lose traction. It actually has to spin backwards, which again, is unlikely.

If one front tire were to hit something very slippery like ice, that tire would spin backwards and the other tire would spin forward with little to no braking force.

 

[Gary Fowler]

I have a 70+ HP utility tractor with FEL and 4 WD. It only takes a second for me to realize I am not in 4 WD when using the loader. It is utterly gutless in 2 WD. I could probably load wood chips with it but as for moving dirt, only 4 WD works. I could load up the rear with weight or ballast but it makes enough tracks in my property with its current weight. Even in 4WD, I have had to use the differential lock occasionally when I cross a ditch at angles and 2 wheels come off the ground on opposite sides of the tractor. It just sets and spins one rear and one front. I am not a betting person, but I would lay some money on a bet that a 35 HP 4 wd tractor will outpull a 50 HP 2 wd when both tractors are bare with no additional ballast or dual wheels etc. Add a fully loaded FEL to both and the 4WD could literally drag the 2 wd around the yard.

 

[bigbull338]

when you have a 4wd drive tractor its like your adding 15% more hp.my tractor is 52hp,an i feel like it pulls like a 62hp tractor.

 

[LD1]

If one front tire were to hit something very slippery like ice, that tire would spin backwards and the other tire would spin forward with little to no braking force.

Agreed. I mentioned this in my post.

But it is unlikely that the front wheels will see such dis-similar traction AND the rear wheels being off the ground.

I have used my tractor ALOT in the winter on my snowy and icy driveway that does have a few hills. I have NEVER had one front tire spin backwards. That is why I said it is unlikely, but not impossible.

 

[scrappy isb67]

Just a safey reminder, front wheels do not have brakes regardless of 4 wheel drive. The most you might hope for is a little engine resistance in the front end but with a 30hp engine even that is minimal. No rear wheels no brakes!!!!

Yes they do, A 4wd (in 4wd) DOES have brakes on the frontend due to the mechanical connection between the frontend and rearend that gives 4wd also allows 4 wheel braking

 

[k0ua]

Exactally:thumbsup:

That is one thing I really hate is the people who say "4wd doesnt mean the front wheels have brakes".

While that may be "politically correct", in reality, whats the difference.

For those that are familiar:

That is like saying that the 2.5T Military axles dont have rear wheel brakes. Since the brake assembly is on the other side of the pinion. In a sense, braking the driveshaft.

Which is exactally what a 4wd tractor does.

The rear brakes are connected to the rear axles, which is connected to the front driveshaft (IF in 4wd). So by applying the brakes (even though the pads are on the rear) it applys braking force to the entire system. INCLUDING the front driveshaft and thus the front wheels.

I guess what I am saying is that the "pads" themselves dont actually have to be on the front wheels for them to have braking pressure applied.

Heck, for that matter, the rear wheels dont actually have brakes. The axles do. The wheels are just connected to that axle that has brakes

That is the best analogy I have ever seen used on this time worn subject. I especially like the last part about the rear wheels have no brakes either, the brakes are on the darn axles. For that matter I guess it would not really matter where the brakes are, as MFWD is "mechanical".. it is all hooked together with gears and shafts etc. IT is as system folks.. and when you slide your happy azz down a hill because the rear wheels have broken loose and you are heading to the bottom in a hurry, you will darn well wish you had left it in 4wd. That's my story and I am sticking to it!

James K0UA

 

[Redneck in training]

That is the best analogy I have ever seen used on this time worn subject. I especially like the last part about the rear wheels have no brakes either, the brakes are on the darn axles. For that matter I guess it would not really matter where the brakes are, as MFWD is "mechanical".. it is all hooked together with gears and shafts etc. IT is as system folks.. and when you slide your happy azz down a hill because the rear wheels have broken loose and you are heading to the bottom in a hurry, you will darn well wish you had left it in 4wd. That's my story and I am sticking to it!

James K0UA

Second that. Learned it the scary way too. I should have put FEL down but it happened so quickly and unexpectedly that I was on the bottom of the slope before I realized what happened. The tractor did a doughnut, balanced on two wheels and then settled on all four. I swear I could clip nails with my rear orifice. It happened when the FEL was empty.

Some tractors have four wheel brakes either standard or as an option. I think Zetor offers four wheel brakes on some models.

 

[Elcid76]

4WD is not an option, it is the only drivetrain worth purchasing for a tractor.

 

[LD1]

4WD is not an option, it is the only drivetrain worth purchasing for a tractor.

I dont think I would go that far.:confused2:

In the op's case, yes, I think 4wd is what he should get.

But a blanket statement like that is either complete nonsense, or from an un-educated source.

There are pleanty of uses for a 2wd tractor. Why would one want to spend the extra money on 4wd if it is not needed for their tasks?? Like baling hay in flat country? Or toting around grain wagons? Or a dedicated tractor (like the farmer down the road) that is only used for its PTO to power grain elevators to load trucks or storage bins? Or pulling a manure spreader?

Most of us on here wouldnt be without 4wd. But then again, most of us arent real farmers. We are just hobby guys that do a LOT of different things with our tractors and get into some sticky situations.