I'd remove the angle gear and drive for a while with it out and see if that kills the noise (I've been doing this for 7 years). See my method for retaining the angle gear sleeve in this thread, first page: https://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=79549&p=428967#top What ...

I'm also having a difficult time identifying the correct sleeve p/n for the 2000...is it 31256008

Thanks Neil....that's what I was anticipating
I appreciate it
Chase

Being under it today showed a good amount of dark oil residue coming from the transfer case possibly the rear main seal I'm not sure but coming from the driver side. No record of transmission service. Engine fluids look golden and timing belt/WP done 10k ago.

I recently bought a 2000 v70xc...today the transmission or transfer case (idk) was whining (very r/c car like) during deceleration and on the freeway it made a large pop then the consecutive popping began, I feel like the epicenter is right under the driver seat . I removed the drive shaft to begin ...