Rear end clunk turning left

Just a few things to do:

Mark bearing caps so they go back on in the same orientation.

Using a dial indicator fixed to the center section get a backlash reading on R&P. When you assemble try and get it as close as possible to what you had or you will be howling.

If it's in the suregrip itself, there won't be any need to disturb the pinion (good thing).