Fasten The Rail To The Motor Unit; Install The Idler Pulley - Craftsman 139.18405D Owner's Manual

ASSEMBLY STEP 2

Fasten the Rail to the Motor Unit

1. 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. DO NOT overtighten.
2. Remove the two bolts from the top of the motor unit.
3. Use the carton to support the front end of the rail.
4. Place the "U" bracket, fl at side down onto the motor unit and
align the bracket holes with the bolt holes. Fasten the "U"
bracket with the previously removed bolts; DO NOT use any
power tools. The use of power tools may permanently damage
the garage door opener.
HARDWARE SHOWN ACTUAL SIZE
Bolt 1/4"-20x1-3/4"
ASSEMBLY STEP 3

Install the Idler Pulley

1. 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 4.
2. Remove the tape from the idler pulley. The inside center should
be pre-greased. If dry, regrease to ensure proper operation.
3. Place the idler pulley into the window as shown.
4. 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.
5. Rotate the pulley to be sure it spins freely.
6. Locate the rail tab. The rail tab is between the idler bolt and the
trolley in the front rail section. Use a flat head screwdriver and
lift the rail tab until the tab is vertical (90°).
Lock Nut
1/4"-20
HARDWARE SHOWN ACTUAL SIZE
Idler Bolt
To avoid SERIOUS damage to garage door opener, use ONLY
those bolts/fasteners mounted in the top of the opener.
"U" Bracket
Bolt
Cover
Protection
Bolt Hole
Lock Nut
Idler Bolt
Screwdriver
Rail
Tab
Lock
Washer
3/8"
Nut 3/8"
Nut 3/8"
9
Bolts
Rail Tab
Grease Inside Pulley
Idler Pulley
Trolley
Connector
Lock Washer 3/8"
CORRECT
INCORRECT