Should front driveshaft spin in 2wd?

[Toro]

After some interior work, I drove around the neighborhood today without the transmission hump installed and noticed the front driveshaft was spinning. It was in 2wd, hubs "unlocked". Factory setup 350/TH350/NP205/Dana 44. I'm guessing there shouldn't be power from transfer case in 2wd on front shaft, and maybe it just spins from going down the road?? Either way, I just noticed and wanted to be sure. Thanks.

[68panelman]

Best way to know if it's not engaged, transfer or hubs, is to crawl under and spin the shaft by hand. Sometimes they will spin slowly at high speed driving, I assume by a vacuum created in the front axle

[Richard]

It can happen. Probably would be from coupling of rotating gears/shafts in the tcase from the oil or excess grease in the hubs coupling to the axle shafts. No offense to previous poster, not sure how a vacuum could be created in the diff or tcase. As the assembly works it would create heat which would equal pressure. There are vents to alleviate that.

[hemi43]

No, the shaft should not be spinning. If it is, most likely something is binding in the transfer case or hubs.
Jack the front of the truck up and spin the front wheels by hand. If the driveshaft spins, then you know there's an issue with the hubs. If not, you will need to remove the transfer case and investigate.
Unless you can drive this truck in space, that diff will never see any vacuum in it.

[68panelman]

Since we are all being comedians and not assuming a plugged vent port, maybe OP has no hose, mud packed, whatever. My turn... before wasting time jacking up front axle, spin the shaft by hands like I said, to see if transfer case is catching, then to test hubs, put transfer case in neutral and then spin the drive shaft again, that will tell you if it's hubs or transfer case. No jacking required. Back to my corner

[Toro]

Thanks for the help. It wouldn't spin freely by hand, but I could hear a clunk on driver's side while trying to spin it in either direction. Upon further inspection, the hub was seized in locked position internally (even though external knob would move to lock and unlock) and in pretty terrible shape in general..., now bumped to top of the list.

[hemi43]

Originally Posted by 68panelman

Since we are all being comedians and not assuming a plugged vent port, maybe OP has no hose, mud packed, whatever. My turn... before wasting time jacking up front axle, spin the shaft by hands like I said, to see if transfer case is catching, then to test hubs, put transfer case in neutral and then spin the drive shaft again, that will tell you if it's hubs or transfer case. No jacking required. Back to my corner

Not being comedians, just setting the facts straight in case someone in a couple years reads this with a similar problem and we don't want them to think that any kind of positive or negative pressure inside the differential housing from a plugged vent will miraculously cause the gears to spin.
Using your method of not raising the front up, how could you diagnose a seized hub only on one side condidering most front axles are an open diff?

Happy to hear that the OP found the issue.