Craftsman 139.53995SRT Owner's Manual page 9

ASSEMBLY STEP 2
Fasten the Rail to the Motor Unit
• Insert a 1/4"-20 x 1-3/4 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.
Do NOT overtighten.
• Remove the two bolts 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 bolt holes.
Fasten with the previously removed bolts.
• 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.
Toavoid SERIOUSdamage to garage door opener,
use ONLYthose bolts/fasteners mounted in the top of
the opener.
"U" Bracket
Bolt
I
Cover
Protection
Bolt Hole
Motor Unit
Bolts _ Sprocket
HARDWARE SHOWN ACTUAL SIZE
[_ Lock Nut
Bolt 1/4"-20 x 1-3/4 1/4"-20
I
I
Lock Nut
SLIDE RAIL TO STOPS
ON TOPAND SIDES
OF BRACKET
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" (30 cm) 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"-20xl-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.
Chain and
Cable
3/8"Lock i
Washer_
I_ 318" Nut
i
Bolt
Trolley _,
Stop Hole :
Inside Pulley
Pulley _
Cable Loop Idler Pulley
HARDWARE SHOWN ACTUAL SIZE
Idler Bolt Bolt 1/4"-20 x 1-314 Lock Nut 1/4"-20 Nut3/8" Lock Washer3/8"
9