NEVER lock the steering on a flat-towed vehicle.
put the tcase AND transmission in neutral, and it should be fine.
if you can find something <beer/soup can?> to seal against the tcase
output for the rear shaft without interfering with the shaft, you can
remove the rear shaft and tape said object in place after THOROUGLY
cleaning the transfer case output housing and the object in question,
and then use high quality duct tape all around the object. Leave tcase
in 2Hi in this case. This will avoid any possible problem. Front shaft
really isn't a concern as the disconnect system will allow it to
freewheel unless youhave a locker up front.
but why not just rent a tow dolly for $100 and tow it behind the moving