Having trouble with my quad I don't have rear wheel drive only have power to front wheels in 4x4 no power to rear in 2x4 or 4x4 hoping it's not a chain or shaft please let me know what you think want to know if it is worth fixing

 

with out you digging in can't give much advice. could be stripped splines on shaft, broken axle, broken diff,
Jack the back up and spin the wheels and listen for noises