Wow! Yep, I hear it. It sounds like a bearing. It could also be the ring and pinion were not properly set up, the pinion nut was over tightened and so on. Do you know which differential it is? It can be any of the following.
Ford 10.25 Inch Rear Axle
9.75-Inch Ring Gear
Ford 8.8 Inch Ring Gear
Let me know and I can get you the specs and procedures.
I listened to it again, and to me it sounds like a bearing. I have a feeling (can't be 100% sure) but it sounds like it's the pinion bearing. If it wasn't torqued properly, it can be damaged.
Let me know.
Wednesday, February 26th, 2020 AT 5:16 PM