Greetings all
I have a 2000 F150 4x4 ,manual trans, V6 103K mies.
At the end of last winter ,I had the vehicle in 4WD and stopped at a store.
When I came out and tried to pull away it felt like the brakes were locked up.
Forward or reverse it was the same.
I disengaged the 4WD and pulled forward and it freed up.
When I got home I put it back into 4WD and drove up the driveway to a steep incline in front of the garage.
Same thing , the truck sat on the incline just like the brakes were applied.
Disengaged the 4wd and the truck rolled down the incline.
I checked the diff's and transfer case and both were full.
The truck runs fine in 2WD.
Any ideas?

 

Would you on a regular basis (once a month or so) put into 4wd? It was recommended to me to do this and in fact is in the manual for my '83 cj7 to drive it 5 mile a month in 4wd to keep things lubed.

 

It's going to bind if you try to use 4wd on a surface that doesn't allow slippage - and it's especially important to run tires with the same diameter on all 4 corners.