A howling noise is usually the result of a bad bearing. Now, it could be a few different ones. Is the mileage correct that you listed? Have you checked the fluid level? If you look at pic 1 below, I highlighted the fill plug. Remove it and the gear lube should be even with the bottom of the opening in the fill plug.
Also, check to see if there are any leaks where the rear driveshaft connects to the pinion shaft. See pic 2.
Let me know what you find or if you have other questions. Please note that this could also be an axle bearing issue, so pay attention if the sound changes when turning one direct or the other.
Images (Click to enlarge)
Wednesday, September 2nd, 2020 AT 8:11 PM