Sears 139.53975SRT1 - Manual (Page 9)

assembly step 2
Fasten the Rail to the Motor Unit
• Insert a 1/4"-20x1-3/4 bolt into the cover protection
bolt hole on the back end of the rail as shown.
Tighten securely with a 1/4"-20 lock nut.
• Remove the two screws from the top of the motor
unit.
• Attach spreaders to the U bracket by snapping
them into place.
• Place the U bracket, flat side down, on the motor
unit and align the bracket holes with the screw
holes. Fasten with the previously removed screws.
• Align the rail assembly with the top of the motor
unit. Slide the rail end onto the U-bracket, all the
way to the stops that protrude on the top and sides
of the bracket.
CAUTION
To avoid serious damage to garage door opener, use
only those screws mounted in the top of the opener.
ASSEMBLY STEP 3
Install the Idler Pulley
• Lay the chain/cable beside the rail, as shown.
Grasp the end with the cable loop and pass
approximately 12" of cable through the window.
Allow it to hang until Assembly Step 5.
• Remove the tape from the idler pulley. The inside
center should be pre-greased. If dry, regrease to
ensure proper operation.
• Place the idler pulley into the window as shown.
• Insert the idler bolt from the top through the rail
and pulley. Tighten with a 3/8" lock washer and nut
underneath the rail until the lock washer is
compressed.
• Rotate the pulley to be sure it spins freely.
• Insert a 1/4"-20x1-3/4 bolt into the trolley stop hole
in the front of the rail as shown. Tighten securely
with a 1/4"-20 lock nut.
HARDWARE SHOWN ACTUAL SIZE
Idler Boll
3»
Bolt 1/4"-20x 1-3/4 Lock Nut 1/4"-20 Nut 3/8'