Hi All, I'm in the process of a total rebuild on a 98 WR400. I have the cases split and just took them and the right side cover to a machine shop to be cleaned. Here is the problem: when he gave me back the case halves he gave me a small ball that might have come from somewhere in the cases. It is a steel ball about 1/4'', I'm not sure if it is from my case or something that was left over in his cleaning tank. Is there a check valve ball somwhere? Oil pump? Also, during re-assembly can/should I use any special assembly lube? Thanks, I'm sure I'll be looking for more advise as I go.