I swapped my cups left to right a couple thousand miles ago and acceleration is smooth. However, when I jack up either of the rear wheels and rotate it back and forth, there is about 3 degrees of slack. I figured out that half of the slack is in the drivetrain. The other half is inside the axle cups. It makes sense to me that the wear mark inside the cup is creating this slack. Does anyone know if adding halfshaft spacers will tighten up the rear end? Suspension is stock.

 

I installed some Megan spacers. My rear end no longer bounces back and forth under instant deceleration, like over speed bumps and after releasing the clutch. The gas pedal feels much more connected to the rear wheels. I think this will also help keep from upsetting the drivetrain balance when accelerating out of corners. I'm not into band-aid fixes but I don't mind spending $100 to put off spending $500 on new inner joints or $900 on a pair of axles to achieve the same effect.

 

The slack is in the diff, the trans and the cups and cv's.