Location of Round Spring?

I have a LG washer, model WM3500CW, serial number 906VWVR1Q303. I took it apart to replace the bearings as it was making a loud noise during the spin cycle. I am putting it back together and have found a round, O shaped spring, and am not sure where it goes. It is approx. 1 1/2 inches in diameter. Haven't been able to find it on the parts diagrams. Any ideas where it goes? Any help would be greatly appreciated. Thanks, Cliff