After removing the pulsator (agitator) it was evident the spline was very worn. Also from looking at the diagram the washer below the pulsator (agitator) was missing since manufacture. I ordered a new washer, pulsator (agitator). The new pulsator appeared to have a steel spline unlike the original pulsator, a new cap because the old one had been removed so many times to tighten the screw down that it wouldn't stay tight any longer. I believe the problem was that the missing washer contributed to the pulsator (agitator) to wear out prematurely. Thanks to AppliancePartsPros' diagram, I was able to order the correct parts especially the washer. Also I asked for next day delivery and sure enough, the parts came the next day!!! I also asked LG for reimbursement for the parts and I am still waiting for their response.