Suzuki: Grinding noise coming from the back of my sj410, sj410, rear tires

Question
I bought an sj410 that has stood in a barn for 6/7 years,when we drove it noticed a grinding noise coming from the rear we cleaned the brakes and the diff oil but still the same there doesn't seem to be any movement in the wheels (bearings)it sounds like rubbing /grinding the jeep moves free when handbrake off the jeep is a 86 c reg and only done 50k it's in excellent condition just can't think what that noise is  

Answer
Put it on jackstands, with the rear tires off the ground,and see where the noise is coming from.  Sometimes the springs that hold the shoes on the backing plate fail, and the shoes drag on the drum without affecting braking.  Or...something neither of us has thought of yet.