It's the combined tolerances of the tranny and the rearend, most of the gears are set-up on the loose side . If it is the driveshaft you need to replace your u-joints asap.
I changed my IRS bushings, upgraded the IRS bolts, installed new springs and had subframes welded in last year. Don’t think it has anything to do with the IRS.
It definitely has some thing to do with the excess play in the drive shaft.
I didn’t have this noise last year when I put the car in storage.
I am probably not explaining it right. I can rotate the drive shaft about a ½” clockwise and counter clockwise and duplicate the noise.
It's the combined tolerances of the tranny and the rearend, most of the gears are set-up on the loose side . If it is the driveshaft you need to replace your u-joints asap.