I’ve looked everywhere and cannot find any succinct answers. At about 20 mph I have a low pitched whirring hum from the rear. This started in Kansas on the way home. The pitch gets higher as the speed gets higher. The noise only happens with light positive torque. Heavy torquing or negative torque, no whir/hum. New fluids in rear, and have never seen anything but a little sludge on the drain magnet. I’m thinking universals? They have at least 150,00 miles on em. One person said it may be a loose baffle in the cheap Chevy muffler resonating. My vote is for universals, however I’ve had them go on domestics and it’s always accompanied with clicking at very low speeds. Ok gurus, any thoughts?
