4wdon dry pavement

[El guapo]

If the 4wd only kicks in when the back wheels slip, why is it potentially harmful to have 4wd engaged when on pavement? Seems its unlikely to slip and therefor the 4wd will never engage, right?

[WOEII]

:lurk:

[825joe]

oh boy......

[El guapo]

What does this mean?

[purplewg]

Think about the tire size difference front to rear. This will change the gear ratio somewhat. If it is locked in 4WD and you are on pavement there is no way other than spinning the tires to keep the drive train from binding up. Off road this binding can be relieved by the tires breaking traction. It is really rough on the running gear. That is the main reason. Another reason is safety. You loose some steering input and turn capability no to mention the increased rollover potential having all four pulling on pavement and making a quick turn.

Now, let me ask. Why would you want to?

[El guapo]

Thanks for the response!
I have no reason to use the 4wd on pavement. I'm really just trying to learn how this machine works.
By what your saying am I to understand that when the 4wd is activated it automatically locks the front and rear axles together? Even if the rear wheels aren't slipping?
(I also didn't realize the front and rear wheels were different sizes. My bad)

[pcbunn]

I learned long ago not to use 4 wd on hard surfaces. I use to drive my 990 tractor over a wooden bridge in 4wd and quickly noticed how much it shredded the wood surface of the bridge. All things considered equal there is just enough difference in the wheel/tire rotational travel front to back to tear up the wood, on pavement all that stress would be transfered to the tires and the running gear. Best to use 4wd only on the dirt or other loose surfaces.