I have a B3350SUHST. I was plowing snow today and had the tractor in 4WD. I noticed every so often one of the front wheels would spin and the other was stationary. I thought if the tractor was in 4WD all wheels including the front would drive. What is going on.
4 Wheel Drive Tire Spin
- Thread starter rancher1524
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85Hokie
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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
4wd is a ..........mmmmm......whats the word???? it is a lie!!!!!
When you have 4wd drive engaged.....the back and the front are both driven - HOWEVER, the front left can spin and the right front stand still as the left rear stay still and the right rear spin!!!!!!!!
YOU really only have 2 wheel drive!!! BUT - there is more, when the diffy lock is engaged, both rears WILL TURN at the same rate, spin or move, but the front does NOT have diffy lock (few do) SO THE best you will ever get IS 3WD with 3 wheels driving.
IN cars/trucks it is the same, Subaru does it a bit differently - ALL 4 will drive the car forward, their system is somewhat unique in the modern world of "all wheel drive vehicles"
That's completely normal.
You have differentials in the front and rear axles, allowing the tractor to turn easily. If one, or especially both, axles are locked up- not differentiating- the tractor would be very difficult to steer.
It isn't a lie, it's physics. For the tractor to turn, the inside front and rear tire covers less distance than the outside tires. Compound that with the front tires turned left or right- they travel a different distance than the respective rear tires. So, differentials are essential for easy operation.
And, to add to that, if traction is equal on both sides of the given axle, both tires will spin. So, it isn't that 4WD isn't 4WD- it's about available traction, and physics.
Consider this, for what it's worth. I have a 1975 GMC truck, full-time 4WD. For that to function, there is a differential in both axles, and the transfer case. Therefore, given the right circumstances, I have 1 wheel drive. If, for instance, the front tires are on ice, and rears are on something more solid, and one of the front tires has less traction than the other- then I have one wheel spinning, while in 4WD. It happens- when pushing snow, I have to put the truck in Hi Lock, to lock the differential in the transfer case.
You have differentials in the front and rear axles, allowing the tractor to turn easily. If one, or especially both, axles are locked up- not differentiating- the tractor would be very difficult to steer.
It isn't a lie, it's physics. For the tractor to turn, the inside front and rear tire covers less distance than the outside tires. Compound that with the front tires turned left or right- they travel a different distance than the respective rear tires. So, differentials are essential for easy operation.
And, to add to that, if traction is equal on both sides of the given axle, both tires will spin. So, it isn't that 4WD isn't 4WD- it's about available traction, and physics.
Consider this, for what it's worth. I have a 1975 GMC truck, full-time 4WD. For that to function, there is a differential in both axles, and the transfer case. Therefore, given the right circumstances, I have 1 wheel drive. If, for instance, the front tires are on ice, and rears are on something more solid, and one of the front tires has less traction than the other- then I have one wheel spinning, while in 4WD. It happens- when pushing snow, I have to put the truck in Hi Lock, to lock the differential in the transfer case.
Larger tractor like the M7040 have a limited slip in the front differential to reduce the one wheel spinning.
Years ago i had a Volvo military truck. It had three switches to lock things so all wheels turned regardless. Very hard to steer in this setting.
Dave
Years ago i had a Volvo military truck. It had three switches to lock things so all wheels turned regardless. Very hard to steer in this setting.
Dave
^What they said, the front is "limited slip" which in the application basically means in a low traction situation like snow, ice, or mud, whichever of the two wheels has less traction will spin. The rear however can be LOCKED.
Geez, hokie, I allways thought you were full of s^&t. Or was that skeet?? Anyway, that was a very good explanation.
RCW
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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Open diff:
"anyone who's been stuck in the mud in Alabama knows, you step on the gas, one tire spins, the other tire does nothing"
"anyone who's been stuck in the mud in Alabama knows, you step on the gas, one tire spins, the other tire does nothing"