shifting into 4-wheel drive

[trixie]

Is it possible to wreck anything by shifting into 4-wheel high while moving? The manual says you can hit the button on the dash at speeds up to 50mph, but, I've heard that damage could still result. I'm on my 2nd trans now, so I don't want to risk wrecking something on this new one.

 

[Webster3]

I have a 94 Sport with the same system as you. You can definetly hit the button while moving, but I would not make the switch while going faster than about 35 MPH with our system

It may be able to handle a 50 MPH switch, but I wouldn't chance it... you'll notice the faster you are going the louder the "clunk" from the transfer case. The newer explorers probably can make the switch at higher speeds though.

Ed

 

[TPLYNCH]

If you do hit it by mistake, just turn it off as quick as you can since you never want to run 4x4 on pavement or other not slippery surfaces...

 

[dman726749]

my question for ford is why would you need 4x4 if you are going 50mph? that seems kinda dangerous

 

[DeRocha]

Switching into 4x4 is not so much a problem for your transmission as it is for your auto hubs. It is the auto hubs which take 99% of the strain of the initial 4x4 engagement. You don't want to hit 4x4 while under acceleration. The harder the acceleration the worse the thunk of the Auto hubs engaging. I let off the gas completely and you can barely feel the Hubs engage at speeds around 40 mph...

As for driving on dry pavement. This is a problem due to torque wind up. This is because the X is a true 4x4. 50% of the power is sent front, while the other 50% is send out back. If the front tires are equal to the rear then all tires turn the same distance per rev. If the front tire is slightly smaller due to underinflation or wear then it will turn slower than the rear causing torque wind up... the rear are turning faster than the front...Now if you had AWD then you would have some kind of opened differential (viscous coupling) at the tcase allowing the power to move freely from front to rear...

It is very important to use 4x4 at least once a week or so for a few miles to keep the front axles moving...this helps move the u-joints around which tend to freeze into position if the lube inside is gone and 4x4 is not used... If the u-joints go they can cause additional strain on your spindle bearings ect...