2001 Polaris ranger 6x6 rear wheels not spinning

[rangerstein]

The middle two tires on 6x6 are spinning. the drive shaft from middle to rear is spinning and the shaft from middle to front is spinning. I have the entire thing jacked up. When I first start it both middle tires will spin and the front two will spin for about 10 seconds. the rear tires do nothing. I can spin the rears wheels both forward or backwards at same time or one forward and one backward and vise versa. Is this normal. Do I have a rear differential broke or is something not engaging the shaft to the gears in the back. Would somebody please tell me how all the drive system works together so I can find something to fix of replace.

[kenfain]

Sorry double post, mods please delete. 

[kenfain]

Iv'e never seen a 6×6 up close. Are there any actuators that engage the rear wheels? Seems unlikely that you would be able to spin one on it's own, unless something came loose inside.

Any diff that I've ever seen, the wheels would spin opposite. Or in a locker, or positrack situation, they're locked to spin together. 

I'm guessing that there's something came loose inside. 

[rangerstein]

I was told by a mechanic that the rear tires engage by a magnet engagement, but I don't see any wires running to the back like the front. 

[kenfain]

Possibly the back are full time engagement, with a broken part inside? That's why it spins independent of each other. Just guessing here, I know little about the 6×6 vehicles. But mechanically, it makes a certain kind of sense. Only one way to be sure though.

[rangerstein]

No grinding going on. Did not hear anthing go wrong.  Was working fine, parked it and came back out later and only middle tires were spinning. I don't think it is full time engagement unless something fell off inside while sitting for 40 minutes. I believe if that happened something would be making noise while I spin back tires.   Somebody that has a 6x6 please help