driveshaft and rear wheels turn hard

Does it run and move... did you have to tow it in the garage......even if it was new I don;t think it will turn that easy....someone else may have to chime in here on this...If you just installed the shifter and the cable linkage...and it will not move when it is running you may have it stuck in between 2 gears that will feel like the rear or trans is locked up...re adjust shifter