No matter what you do, Low range or not, there's not diff lock, it's just Limited slip... so only one tire will spin anyway. it's just that with the lsd it's a little better off road with picking which tire to spin. It's no where near a locker. As for the noise, when i'm in low I hear the transfer case and a little whine down there when under a heavy strain, but nothing loud or anything. Check the level of fluid in your diff and add the additive if you know it's coming from the rear diff.. same with the transmission. But 4wheel drive is never all 4 wheels unless you have lockers front and rear.