Jmpu671

So before I get flamed for this.... yes I have read through most rear noise post and have done the following:
Re-torqued the Axel nut.
Inspected the CV shafts for damages.
Checked my Diff fluid(little bit of metal flake no big chunks and not an unusually high amount of sparkle) replaced with new fluid.
Tightened all Driveline bolts to spec
Tightened all Suspension bolts to spec
Coil Overs are not blown
Rear Tire Pressures are equal
New tires mounted and balanced
New Brakes
All Brake hardware inspected for damages and operate as normal

My S has 150,000 miles on it.

Heres the issue im having. After being parked for a few hours and everything cools down. I reverse and proceed to take off. For the first few seconds there is a really loud grinding kinda clunking sound coming from the rear you can even feel it. Sound does not happen when reversing only when going forward and only for a few seconds. The sound goes away and the car drives normally. I am about to purchase bearings and hubs for the rear as I am pretty sure that they need to be changed. The car is now parked until I figure this out. Put maybe 15 miles on the car when sound came up. Was having the popping noise before from having rear axle nut not torqued to proper spec but that noise went away after I torqued them to new 180 ft/lb + 60 degrees spec. Figured while I have the car up on jack stands again might as well check other possibilities. Please chime in if you have had any similar experience I want to make sure everything is all good on my car for the next few thousand miles.

Thanks,

JMPU671

street_ruler

check your carrier bearing first. often called a "center driveline support bearing" or some combo of those words

Jmpu671

It was the drivers Rear bearing completely toasted. Pulled the knuckle off and found a thick mixture of Dirt and Grease. Pressed out the Hub to find there was no grease in the bearing at all. Ordered a new set of bearings and hubs gonna do both to start off fresh. Thanks for the feedback.