Fastenthe Rail To The Motor Unit And Install The Idler Pulley - Craftsman 139.53903DM 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 overtighten.
• Removethe two bolts from the top of the motor unit.
• Placethe "U" bracket, flat side down onto the motor unit and
align the bracket hole with the bolt holes. Fastenwith 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.
HARDWARESHOWN ACTUALSIZE
Washer 5/8" Lock Nut 1/4"-20 Spacer
Bolt 1/4"-20x2-1/2
To avoid SERIOUSdamageto garage door opener, use ONLY
those bolts/fasteners mounted in the top of the opener.
Bolt
1/4"-20x2-1/2
u
Washer 5/8"
Spacer
Cover _)
Protection
Bolt Hole
Hex Screws
832x7/16" -_1 _
_ Chain
_- Spreader
Bolts
I
_ Motor Unit
Sprocket
Spacer J ""r" SLIDE RAIL TO STOPS
t ON TOP AND SIDES
OF BRACKET
Washer 5/8"
Lock Nut
1/4"-20
ASSEMBLY STEP 3
Install the Idler Pulley
• Laythe chain/cable beside the rail, as shown. Graspthe end of
the cable and pass approximately 12" (30 cm) of cable through
the window. Allow it to hang until Assembly Step 5.
• Removethe tape from the idler pulley. The inside center should
be pre-greased. If dry, regreaseto ensure proper operation.
• Placethe 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 underneaththe rail
until the lock washer is compressed.
• Rotatethe 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
Bolt
Washer
_ldler_
Bolt W
Lock i
Washer
3/8" i
I_ Nut 3/8"
I
Screwdriver Trolley
Bolt
Trolley
Stop Hole,
_ Grease \
-.. Inside Pulley \
__ Idler
_Lock
Idler _ Nut
Pulley i
Idler Bolt
HARDWARESHOWN ACTUALSIZE
Bolt 1/4"-20x1-3/4" Lock Nut 1/4"-20 Nut 3/8" Lock Washer 3/8"