I have a McCoulgh (sp) line trimmer. the entire head is comming loose from the "pole". I have checked, tightened and recheck all bolts and screws holing it on. it still moves as if its wanting to spin around. Its only about a 1 inch move but its enough to screw up trimming. any suggestions. its is a res model. I want to get a Stihl or something commercial next year, but I need this to last this year.