So im going to be taking my aunt's old rainbow apart because it's very loud and has an awful vibration to the point where is vibrates the wheel dolly off if you pick it up. When she bought her e series in 02 the dealer took it and she said this is how it came back. Im thinking its the bearings but when you turn the separator by hand its smooth and quiet. So that got me thinking maybe he got the fans in backwards or didn't get them tight because to me it feels like its not at full suction. Doubt the fan are that dirty cause it hasnt been used much at all. Aside from the fans being in wrong, fan holes bigger than normal, or bad bearings is there anything else I need to be on the look out for?