Sounds like the axle disconnect is working
. Can you shift back out of 4wd and put it into 2wd? When I talked to the P.O. he said it took him a few days to get it back out of 4wd.
If the front axle is locking up it, I am thinking it must be in the gears. When in 4wd the passenger side shafts become engaged and the differential acts like a open diff just like the rear. The fact that it rolls about 5 feet with 33" tires would equal 3/4 of a rotation ( 33"x 3.14= 103.62 103.62"/ 12"= 8.64 ' I'm stuck on the couch, and I'm a Nuke). If it was the transfer case, the largest gear for the 4wd activation is only about 5", so 1 rotation is 15.7" so the math alone points to the differential.
Pull the front drive shaft and then shift into 4wd. The axle disconnect will slide and engage. Try to drive and see if it still locks up. If it does it is in the gears, if not I would then suspect the transfer case.
Have you tried shifting in the 4wd low and trying it? Do not give it much gas, since the lower gearing could cause something to break if it is binding in 4wd Hi.
The more info you can tell us the better we can keyboard analyze.