I seem to have issues with most if not all of my brand new red WMS rear gears too. Never have issues with my horstman'sI can attest that we’ve had multiple brand new gears be junk, from WMS and the generic gears. Not a solution but be mindful of quality control with the new stuff,
If you use the clamp on one's that use 2 pinch bolts, make sure to tighten each bolt in increments so that the gaps are even for both boltsI have this problem on my slack pursuit. with the light weight 4 bolt hub the one with the set screw. I've indicated axle even crank for runout nothing. I can see by eye the sprocket bounces even with sprockets for the 4 bolt hub I discovered. I couldn't find a good way to indicate the hub. I think my hub is bad. What does everyone recommend from hubs. I was thinking floating or clamp on idk 4 or 6 either. Also on the clamp on one's to you leave a little clearance between clamps Thanks in advance.