Fasten The Rail To The Motor Unit And Install The Idler Pulley - Craftsman 139.18489D Owner's Manual

ASSEMBLY STEP 2
Fasten the Rail to the Motor Unit
• Insert a 1/4"-20x2-1/2 bolt, washer and spacer into the
cover protection bolt hole on the back end of the rail as
shown. Install lower spacer and washer then tighten
securely with a 1/4"-20 lock nut. Do NOT over tighten.
• Remove the bolt and lock nut 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 onto the bolt,
mounted on the motor unit and align the bracket hole
with the bolt hole. Fasten with the previously removed
bolt and lock nut.
• 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.
HARDWARE SHOWN ACTUAL SIZE
Washer 5/8"
Bolt 1/4"-20x2-1/2
ASSEMBLY STEP 3
Install the Idler Pulley
• Lay the belt beside the rail, as shown. Grasp the end
with the hooked trolley connector and pass
approximately 12" (30 cm) of belt through the window.
Keep the ribbed side toward the rail, and 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.
Idler Bolt
Spacer
Lock Nut 1/4"-20
HARDWARE SHOWN ACTUAL SIZE
To avoid SERIOUS damage to garage door opener, use ONLY
those bolts/fasteners mounted in the top of the opener.
Bolt
Washer
Spacer
Cover
Protection
Bolt Hole
Spacer
Idler
Bolt
Lock Washer
3/8"
Bolt 1/4"-20x1-3/4" Lock Nut 1/4"-20
9
Bolt
Lock Nut
"U" Bracket
SLIDE RAIL TO STOPS
ON TOP AND SIDES
Washer
OF BRACKET
Lock Nut
Bolt
Pulley
Nut Washer
Screwdriver
Grease
Inside Pulley
Idler Pulley
Nut 3/8"
Trolley
Connector
Nut 3/8"
Motor Unit
Sprocket
Rail
Bolt
Trolley
Stop Hole
Idler
Lock
Pulley
Nut
Lock Washer 3/8"