yo!
You can try a few thAngs before pulling the hubs & Dana44 apart to inspect;
Operational Test; "... (engine off, hubs disengaged), crawl under the truck with the transfer case in 2HI, you should be able to grab the front drive shaft and turn it by hand. Also with the hubs disengaged you should see the front axles turning freely. Now engage the hubs and you should not be able to turn the drive shaft by hand. Jack the front wheels off the ground with the hubs engaged, turn the drive shaft by hand, the wheels should turn. The 4x4 light should not be on in 2HI, when in 4LOW you may have a low range light on, (not all trucks have that light) at least mine doesn't..."
Source: by Seabronc (Rosie, Fred W) at broncozone.comOperational Test; "...To CHECK FOR PROPER ENGAGEMENT, dial both hubs to LOCK and raise the front left corner of the vehicle off the ground. Spin the lifted tire. The drive line will turn if the Hub is engaging properly. TO CHECK FOR PROPER DISENGAGEMENT, dial the lifted wheel hub into FREE and spin the lifted wheel. If the drive line does not turn AND you hear NO ratcheting sounds, the hub is disengaging properly. Repeat step 5- 6 with the right wheel & hub. NOTE: The hubs are not required to seat against the wheel housing when installed, they may move in and out quite easily. This “float” is normal and will not affect performance..."
Source: by Warn®"...Manual Hub - The t-case disconnects the front driveshaft from the transmission, and the hubs disconnect the axleshafts from the wheels. The driveshaft is ALWAYS connected to the diff & axleshafts. Depending on how tight your diff is, both axleshafts MAY turn when you turn the d'shaft while BOTH hubs are unlocked, but at least one of them has to no matter what. If the d-shaft won't turn with both front wheels off the ground (or the hub locks removed), then the t-case is still in 4. If either axleshaft won't turn with its hub UNlocked AND the t-case in 2 or N, then that hub is stuck locked. I suspect you'll find some carmelized grease, and some surface rust on the lock rings, and probably a spring or 2 heavily rusted, to the point that they're ruined. But that's just a guess. Take both hub locks OUT of the hubs, and then roll the truck a little. You don't need to remove the tires, or even jack the front end up since the locks don't bear ANY weight. If the d'shaft still turns, the problem is in your t-case....."
Source: by Steve83