2002 dodge 1500 rear end making whining nosie

This could be one of several problems: If the noise increases with speed, and you are only hearing it from the rear differential and not the transmission, it could be the rear differential carrier bearings, or rear axle bearings going bad. If you are only hearing the noise upon acceleration or deceleration, the rear differential ring and/or pinion gears may be going bad and the rear differential will need an overhaul. You'll have to get the rear wheels off the ground and see if you can pinpoint the location of the noise with something such as a stethoscope. If it's coming from the rear differential, you'll need to pull the bolts and the cover to determine if the gears are still in good shape, or if there is any pitting. Same with the carrier bearings; if you see pitting/ discoloration, they'll need replacement. If the noise is coming from one side towards the end of the axle shaft near the wheel, it's most likely a axle bearing going bad, and you'll need to pull the wheels, remove the diff. cover to release the C clip which holds the rear axle in place at the differential, and pull the axle out. You also need a special tool with a slide hammer to remove the axle bearing and seal.