our headers are washed inside and out end season greased all metal parts treated out side waxed and i can't really say we have had a bearing failure due to water but the baby sure sparkles...and we have no problems with rats we remove all the sieves and get in and give her a good going over inside gives a chance to see what needs doing in the off season...a truck wash cleaner low pressure is magic for cleaning the panel work..i find the air just blows dust all over the place including the operater and the mud well some times that is just get in with the hands and dig it out