Ran across this problem last week and did the job today. This Sakai roller had all the hydraulics quit on it. I knew it was a pump drive problem but ended up not being what I was expecting.
If the hub screw comes loose or the splines wear, the hub vibrates its way toward the flywheel and ends up disengaging both the pump splines and the drive plate splines. I was expecting the teeth on this plate to be gone..............was not the case.
A plastic pilot insert would have prevented this.....but there is nothing. I went ahead and installed the new drive plate, new hub and plate retaining bolts. I cleaned the shaft and new hub, installed Loctite on both, and squeezed that new clamp bolt as much as I dared. Hopefully it will stay there.