The TV lift in my 2009 Big Horn 3400RE is binding and the TV can no longer go up or down. Unfortunately, the TV is not in the stowed position for travel. I have taken the TV off the mount and can see two thing happening. First, the back bracket that holds the top roller chain sprocket is twisting inward/outward as you try to put the TV up or down and this happens no matter if the TV is attached to the lift or not. Secondly, with the TV off the lift, I can see that the top roller chain sprocket bushing is reamed out and the metal shaving on the floor below it confirms that the sprocket is damaged. Please help. Part number for the sprocket, phone number where to order it. Thank you!