8.75 axle question-easy question???

Jack both sides, try to spin each side to make sure a brake is not locked up on either side, lower one side back on the ground. If the raised side still spins, its not a sure grip or power-loc. Of course all this has to be done with the trans in nuetral or the driveshaft removed if it is a posi. If it's not, one side should turn even in park; in fact if both sides are off the ground each wheel would spin in opposite directions.