I was recently mowing with my rotary cutter and noticed a clanking sound. I stopped the machine and noticed that one of the snap rings was missing on the rockshaft that controls the lift arms on the 3PH. The missing snap ring allowed slack from side to side that was causing the clanking sound. An O-Ring also had come out of place because of the slack. I pushed the O-ring back in place and installed a new snap ring. There seems to still be a small amount of slack but i think that is normal. My question is could this have affected anything else internally? it seems to work fine. What is the purpose of the O-ring? I could never figure out what actually engages the Rockshaft that makes it rotate and lift.