Liftmaster Chamberlain 81C168 screw drive carriage rack
Works on Liftmaster, Sears Craftsman and Chamberlain garage door opener rails from 1995 to present.
Works in conjunction with carriage trolley part number 41C4677
QUESTION: The screw drive carriage rack is binding at the end of the rail that is at the garage door end? How do we fix this? by Ed E 6/15/2013
ANSWER: As I recall that means your torque is too loose- it needs to be reset - I believe the option on the left clockwise- at least on my model opener by P A a