Craftsman 139.53989 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 over tighten.
• Remove the two bolts from the top of the motor
unit.
• Place the U bracket, flat side down onto the motor
unit and align the bracket hole 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.
• Attach spreader to the motor unit with two screws.
HARDWARE SHOWN ACTUAL SIZE
I_ Lock Nu @
Bott 1/4"-20 x 1-3/4 1/4"-20
To avoid SERIOUSdamageto garage door opener,
use ONLYthose b01ts/fastenersmounted in the top of
the opener.
Bolt
I
Cover
Protection
Bolt Hole
\
Hex Screws _t-tl
8-32x7/16" 'r
I ]
E
_Chain
Bolt _ Spreader
I
I
i Motor Unit
i
SLIDE RAIL TO STOPS
ON TOPAND SIDES
i Lock Nut OF BRACKET
ASSEMBLY STEP 3
Install the Idler Pulley
• Lay the chain/cable beside the rail, as shown.
Grasp the end of the cable 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.
Idler Bolt
HARDWARE SHOWN ACTUAL SIZE
,/i/i//j jl J11)
Bolt 1/4"-20 x 1-3/4 Lock Nut 1/4"-20 Nut 3/8" Lock Washer 3/8"