I doubt that it's a bobby pin. The noise more than likely comes from the belt. Perhaps it's starting to fray. You can inspect it from the rear of the washer by removing the back. This diagram show the parts required to take the tub out if the belt is ok. http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5226697&diagram_id=25498827#d25498827
Answers & Comments
I doubt that it's a bobby pin. The noise more than likely comes from the belt. Perhaps it's starting to fray. You can inspect it from the rear of the washer by removing the back. This diagram show the parts required to take the tub out if the belt is ok.
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5226697&diagram_id=25498827#d25498827