4x4 ?

[Mark Page]

I've probably owned 6 4wd vehicles over the past 20 years. Pick Ups, SUVs etc. Everyone would buck when you tried to turn in 4wd. With the 4wd engaged my new Massey 2615 w/mfwd will not buck no matter how sharp you turn or what speed. Why is this?

 

[murphy1244]

I've probably owned 6 4wd vehicles over the past 20 years. Pick Ups, SUVs etc. Everyone would buck when you tried to turn in 4wd. With the 4wd engaged my new Massey 2615 w/mfwd will not buck no matter how sharp you turn or what speed. Why is this?

You sure your really in 4 wheel?

 

[Soundguy]

does it use cv type front axles ?

 

[JerryG]

On tractors the front gears are faster than the rear. Thus the front is pulling the tractor a small amount faster. On a auto the front and rear use the same ratio or extremely close.

 

[Raspy]

It probably because you are on dirt and because the rear has much more traction than the front. Also, there are no springs to allow windup or bouncing. So the front slips a bit and it's no big deal. Mine does the same thing, smooth on turns even in 4WD. I notice that there is some slipping going on, but it doesn't jump like my my pickup does.

The axle ratios are not designed to make the front pull the tractor. The difference in speed cannot be corrected with a ratio difference because the speed difference is dependent on how sharp you turn. It's always a different ratio between the front and back. They are designed to run smoothly when going straight with the correct ratio for the different size tires.

 

[andrehoude123]

Also if you don't have your diff locked up in the back it's only a 3x4 so your 2 front wheels and one back wheel and it's usually the outside one turning in a corner witch pushes you thru the corner my l45 will not but on 4x4 but in 4x4 with the diff locked up its a rough corner

 

[mikehaugen]

Also if you don't have your diff locked up in the back it's only a 3x4 so your 2 front wheels and one back wheel and it's usually the outside one turning in a corner witch pushes you thru the corner my l45 will not but on 4x4 but in 4x4 with the diff locked up its a rough corner

This is kind of a misconception. An open dif applies equal torque to both wheels at all times. If there is no wheel spin, both wheels have power... even in a turn.

 

[DarkBlack]

That is true. Equal torque, but likely unequal power. Confuses almost everyone.

 

[LD1]

4x4 is 4x4 no matter what combination of open diffs, lockers, posi's, or spools. You may only see 2 wheels spinning, but the other two wheels are trying to drive with the exact same amount of force as the ones spinning.

True, in can be unequal "power" if we are talking horsepower. but just "power" is too broad of a term.

Horsepower is 0 if there is no rotation. So while torque is being applied to try to turn the wheel, if traction is great enough that it dont spin or roll, then yes, technically, there is no horsepower.

As to why the tractor dont buck like a truck, I think it is a combination of what most others posted. First, the fronts do rotate a tad faster, so that helps. But with everything being ridgid and no suspension, they just slip and you dont know.

There were/is exceptions to the trucks though. Old full time 4wd trucks with a 203 t-case didnt buck, cause they had a differential gear in the t-case just like the axles. It allowed one axle/driveshaft to rotate at a different speed.

 

[mikehaugen]

Have you tried it on pavement?