I have an 894 side delivery hay rake. The left tire bolts to a drum hub. This drum hub goes over the hand clutch, which drives the chain when it's engaged. My question is how does the hub secure to the hand clutch? From all I can tell, it just slides on to it. Then the tire bolts onto that, but what keeps everything in place? I have the operator's manual but it doesn't show how this is secured. Is there some kind of pin that goes through the axle on the other side of the tire to keep it in place?