prevents the shaft for sliding out.http://www.ehow.com/how_7600635_undo-rivets.htmlhttps://sew4home.com/comment/1734
You must be able to remove rivets on the plastic bit and slide it back in the metal back in. you might need to source new rivets to fix it back again.The grooves on that plastic bit is what prevents the shaft for sliding out.Bit of DIY to do on rain hampered days.http://www.ehow.com/how_7600635_undo-rivets.htmlhttps://sew4home.com/comment/1734