07 rincon drive train noise

I just bought an 07 rincon after driving about 50 miles or so I keep hearing a moaning noise in the drive line it’s worse when I push on the throttle then seems to go away when I let off I thought it was the bearings in the final drive so I took it out and the bearings are fine! Also I wiggled the wheels the wheel bearings all seem to be good! I took sealed bearings
out of the final drive and my new ones are not sealed which do I need any help would be great also could it it be the pinion bearing it seems to spin fine and doesn’t have any play!