That is a common problem. New, off-the-shelf clutch sure-grips are rarely assembled correctly. If a fresh change of gear lube and friction modifier doesn't do the trick, I would disassemble the unit, clean everyting then de-burr the casting around the clutch ears if needed. Be sure to pre-lube the clutch plates with straight friction modifier on assembly.

I prefer Ford friction modifier because it is actually rebranded OEM Spicer stuff.