Well, no more dead batteries so far! :fingerscrossed:
I replaced the entire rear control arm with new bushings pre-installed. One of the bushings that I pressed in already failed. Since I just had it apart recently :doh: , the swap went really easy. :rolleyes2:
Unfortunately it didn't fix the groaning coming from the rear end. I'm starting to think it's not a suspension problem and it was just a coincidence that it showed it's face when it did. My running theory is that it's the LSD engaging in tight turns and moaning from the stress on pavement. I added some more LSD friction modifier and it seems the sound has gone! :wings: Hopefully I didn't add too much modifier (originally 4oz, added 3oz more) and cause other issues. :idontknow: