Assembly Step - Chamberlain Power Drive Security+ PD612C Owner's Manual

ASSEMBLY STEP 1

Assemble the T-Rail and
Attach the Cable Pulley Bracket
NOTE: If T-rail is not assembled exactly as shown,
trolley will not travel smoothly along length of rail
or it will hit against nuts.
NOTE: When tightening the bolts, be sure to keep
bracket parallel to the rail. Otherwise, the rail may
bow when the opener is operated.