Rear end noise

Okay so I have a 2008 mustang base model (4.0L v6), but I have recently swapped the stock rear end for an 8.8 out of an 05 GT. I took it for a test drive and started hearing some noise. I have checked a few things but nothing has seemed to fix it so I figured I'd put it out here to see if anyone else had any ideas. The link is below so you can listen for yourself

What drive shaft did you swap too?

Have u looked under the car to see if there are any rubbing marks?

Verify the pinion angle?

The drive shaft is the stock v6 one, I swapped the 8.8 flange with a cobra flange so it would be a direct bolt on.

I did check around the calipers for rubbing but I haven't had a chance to jack the car up yet to get under it and check there.

As far as the pinion angle goes, I am not sure

Another thing I forgot to add is that the sound only happens when the car is coasting at low speeds and it almost seems to get louder when I hit the brakes

Since you hear noise on decel & changed the pinion flange: I suspect you didn't get the pinion flange tourque correct.

I hear some grinding noise rhythm? Do you know the driving speed? Than you can measure the frequency of the noise from your recording and if it has the same freq as the wheel, its connected to the differential carrier, if its 3.x higher its pinion/driveshaft.

I am not sure of my speed in the recording. Based on some research I’ve done and some similar sounding recordings that I’ve found online I’m thinking it’s a pinion bearing issue. Either it had a bad bearing when I bought it or it’s because I torqued the new flange down too much. Since I don’t have the tools needed to replace pinion bearings (if that is the case) I decided to just take it to a shop. I hate to take it in but I don’t really have the time to pull it apart or the extra money to fix it if I some how make things worse.

I appreciate everyone’s input and I will continue to post updates as I hear from the mechanic so this thread might help others in the future who have the same problem