This should be pretty straight forward for your friends to trouble shoot. Have them put it in 4 HI and make sure the hubs are unlocked. Drive it slowly as someone walks next to it and watches the front drive shaft. If the DS turns then the tcase is engaging the front drive. Repeat the same test in 4 LO. If the DS turns the tcase is engaging. Next, put the tcase in 2 HI and lock the hubs, repeat the slow drive by. If the DS turns, assuming you dont have a locked front axle, then both hubs are probably OK. If not, you probably have an issue with one or both hubs.
Just to be clear, you do have the dual stick tcase shifter made by Advanced Adapters specifically for the Orion, correct?
Even with this shifter setup you have to make sure it is properly adjusted. On my Orion it was the last 1/8" of stick movement that engaged the front drive shaft. Make sure the shifter is properly adjusted and that the stick travel is not being limited by the sheet metal of the floorboard or even the rubber of the boot. If so, you may need to open up the size of the hole in the floorboard. I even had to heat up my shifter stick and bend it back slightly to keep the knob from hitting the dash board. Once I did all of these things to mine, it would reliably go in to 4WD, both Hi and Lo, and not pop out.
Randy Rosetta KDØKWX TLCA #19351 69 FJ40 "Meanie" & 1970 Boss 302 Mustang