I was recently checking out my 4 wheel to make sure it seemed to be engaging and disengaging properly. Please keep in mind that I'm on dry pavement (live in Phoenix) so I'm just doing a quick check on a short run. I selected 4x4 low and begin to back the truck out of my driveway with the front wheels turned. The vehicle wouldn't back up because of of being in 4 wheel, so I decided to switch it back to 2 wheel. It still didn't want to back up so I flipped. I shut off the motor and jacked up the back passenger wheel. The wheel spun like 1-2 rotations. After that, the vehicle backed up without problem.

Next, I stopped down the block and once again selected 4x4 low. I had no problems with driving it until it would turn (expected that). When I went to pull back into my driveway, again I found that the binding was a little much so I switched it back into 4x2. The vehicle still didn't want to move forward very well. I then put it in reverse and backed up 5 or so feet. At that point, everything was back to normal.

It seems like the transfer case and/or hubs don't disengage from 4x4 low to 4x2 on dry pavement unless a motion opposite of the one travelling in 4x4 low is travelled. Does this sound like normal operation?

 

your tires need to be able slip, 4x4 and ESPECIALLY 4LO should NEVER be used on dry pavement, because, as you noticed, you get some nice binding up. youre lucky you didnt damage the drivetrain especially in 4LO. they should only be used in conditions where your tires have the ability to slip some to negate the binding

 

Thanks, I didn't know that a short trial run would be a problem. I'll make sure never to try that again.

 

Uh, yeah, don't do that!

What year truck do you have? If it's an '01 or newer (or whenever the heck the change was, '02+ for sure) then you don't even have dis/engagable hubs anyhow. Ford elmintated the hub disconnect and went to a 'live axle' setup where the front half shafts are ALWAYS connected to the wheels, regardless of transfer case position. The upside is there are no pneumatic or electronic hubs to break anymore. The downside is your CVs are ALWAYS turning (and racking up wear and tear). My service advisor read me a line that it keeps the boots plyable and prevents them from dryrotting. I'm not sold.

This means you should never ever run 4WD on dry pavement, and even then you should never ever ever ever turn the steering wheel. As has been said, your fortunate that it just bound and didn't break. Were you do have thinner tires and/or heavier duty drive train components I think you would get wheel hop instead, as the tire contact patch w/ the ground would be the weak point. My friends that have been driving 4WD trucks for years say they've had that happen in the past. I haven't had the gonads to try it..

 

you know how to get in and out of 4low right?

Neutral/park, foot on brake, not moving (takes 10+seconds esp if its cold out)
if you have a manual add holding in the clutch.

Live axle is 2001+
pulse vacuum hubs (?)was 98-00
xx-97 was some other kind of hub.