All wheel drive

[Ron D.]

My F13D is always in all wheel drive. It does not have a lever for 2 wheel drive only. With the front wheels off the ground, if you rotate one wheel, the other front wheel rotates the opposite direction. Does anyone know anything about this drive system? I was curious as to how I could rotate the front wheels with the back wheels still on the ground. I know the front wheels pull.

I know this is a little know about model, but thought I'd ask.

Thanks,
Ron

 

[Ken Cunningham]

The front differential is why the front wheels will rotate in opposite directions while the back wheels stay still.

 

[nostep]

The tractor (and most four wheel drive trucks) have what is called four-wheel drive. In reality, they are two wheel drive. There are two drive shafts, one front and one rear. Those are tied together, probably with a gear ratio between them to account for different tires sizes. When the engine is off or in neutral, those shafts do not spin. When the shafts are spinning, the front and rear diffs each get that energy and in turn (pun intended) provide rotational energy to the differential gears. Those gears will allow both wheels to turn at the same speed (front or rear) if you are going straight. On a turn, the differential gears will allow one to turn faster and one slower, but both are still helping you go forward. If one front and one rear wheel were to get onto ice, the four wheel drive vehicle would be stuck. This is due to the nature of the differential gears and the need to be able to turn a corner. This is all true if you do not have posi-traction or a differential lock, but that's a story for another time . . .

 

[Cord]

The wheels turning in opposite directions is common with open differentials. What's interesting is that you can turn the front wheels while the back ones are still on the ground. Typically I would say that this would not be possible in 4wd. Yet you say that 4wd works. Strange!

 

[tallyho8]

If you jack up the rear end of any car you can turn the wheels even while it is in park but one wheel will go forward and one backward. If you put it in neutral then you can turn both wheels forward.

 

[nostep]

Tallyho8 is correct, you should be able to turn one wheel and the other will spin opposite. The driveshaft will not be turning during this. That is normal. There will be a difference if you do that to the rear and the diff lock is engaged. With that, neither wheel will spin without the driveshaft spinning . . .

 

[Ron D.]

I also found it odd that the front wheels would turn without the back wheels turning, but Tallyho8 and nostep explaned it well. Thanks for all the info., it's greatly appreciated.