4WD and Dry Pavement

[pulleye16]

I was wonder if this is a myth or reality. Can driving your truck with 4WD engaged really be bad? Can some please explain why?

Today, it was partial raining / snowing, and even though the roads were probably perfectly fine, I had my truck in 4 wheel. I guess I'll put mine in 4 wheel just to be "safe" sometimes cause rear wheel drive can be a Bit@$ if you hit some ice.

If 4WD is bad when the roads are dry, what do you guys do when it's "iffy?" What if 90% of the hwy is perfect dry but cause of unknown black ice potential, do you do?

Thanks

[Macgyver55]

Reality... if you dont have full time 4wd. Driving on dry pavement in 4wd with part time systems, will cause a condition called axle wind up. It occurs when the two axles turn (even at very slightly) different speeds. After a distance it causes growing strain on the driveline components because they are trying to turn at different speeds with no allowance for slippage in between the front and rear. Full time systems have clutches incorporated that will allow for slightly different speeds to allieviate the chance of it happening. You dont want to find out the hard way what will happen, and it can be expensive. Wet pavement is another thing, it will allow for slippage.

Search "axle wind up", you'll find several good explanations to help you make sense of it.

[highlife4me]

What you were doing would be just fine, just remember to slow down if the roads are questionable.

[BobT]

Beware! Driving in 4wd at highway speeds is not recommended. In 2wd, if you go into a spin you can let off the throttle and steer your way out of it. In 4wd, you might as well let go of the steering wheel because you have virtually zero control. Found this out the hard way. Also, it is very easy to forget how icy it really is and you will drive too fast for conditions. Use the 4wd to get started from a stop on ice but once moving shift back into 2wd for safest driving.

[delcecchi]

Remember 4wd does nothing to help you steer or stop, both of which are important.

[Esox_Magnum]

Auto 4x4 when it's iffy, kicks in when needed.

[BobT]

Remember 4wd does nothing to help you steer or stop, both of which are important.

In fact, steering can become more of a problem in 4wd than 2wd.

[Jeremy airjer W]

If there is a little snow and ice on the road it is probably enough to allow for a little slip.

I Also agree that your better off in two wheel drive until conditions either require you to slow down or warrant four wheel drive.

I drove last night for over 200 miles in the winter weather and never needed four wheel drive and still made good time.