Lay the new chain and cable assembly beside the rail.
Grasp the end of the chain cable and pass approximately 12 inches of cable through the rail window.
Add general-purpose grease to the idler pulley center hole if it's dry.
Insert the idler pulley into the rail window behind the chain cable and line up the mounting hole.
Reinstall the idler pulley bolt and tighten it firmly with the lock washer and nut.
Make sure the idler pulley spins freely after tightening the nut.
Connect the chain cable to the retaining slot by pushing the pins of the master link bar up through the cable link and trolley slot.
Push the master link cap over the master link bar pins and past the pin notches.
Slide the clip-on spring over the master link cap and onto the pin notches until both pins are securely locked in place.
Position the inner trolley to the previously marked position on the rail.
Align the rest of the chain and cable assembly along the rail, routing the cable onto the idler pulley and threading the chain through the chain spreader and around the motor sprocket, making sure not to twist the chain.
Connect the trolley threaded shaft to the new chain by pushing the pins of the master link bar up through the threaded shaft mounting hole and the end link of the new chain.
Push the master link cap over the master link bar pins and past the pin notches.
Slide the clip-on spring over the master link cap and onto the pin notches until both pins securely lock in place.
Thread the inner nut up to the top of the trolley threaded shaft and reinstall the inner lock washer on the threaded shaft.
Making sure not to twist the chain, insert the trolley threaded shaft through the hole in the trolley. Using channel lock pliers, apply tension to the trolley.
Insert the lock washer on the trolley threaded shaft and loosely thread the outer nut onto the threaded shaft.
Tip: Have a helper push the inner trolley toward the threaded trolley shaft to apply more tension to the chain and cable, making it easier to thread the outer nut onto the trolley shaft.