The transfer shaft does not transmit power to the driving shaft through ring gear?

This vehicle sometimes vibrates heavily when climbing unlevel roads and most of the time when you engage reverse gear, it will drive small and stop and when you depress throttle pedal, it vibrates heavily before driving. Sometimes when you throttle it to run faster, before shifting to second gear, it will vibrate. Then 2 days ago I drove this vehicle over distance of 120km and there was no problem at the highway, then when I reach the destination, about to climb unlevel culvert to park, the vehicle could not drive again both drive and reverse but I noticed that while on drive, if I throttle it, the speedometer will be rising and shifting gears while at stationary. Then I off the engine and engaged park, the vehicle was still rolling, I put the wedge and noticed that shaft is not locking. I loose the gear tail and check output gear and transfer gear, both were locked. At this point I suspect transfer shaft to ring gear misalignment, broken seaten or out of position, how do I check this without removing the transmission?