Fastenthe Rail To The Motor Unit And Install The Idler Pulley - Craftsman 139.53920DM Owner's Manual

ASSEMBLY STEP 2
Fastenthe 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.
Tighten securely with a 1/4"-20 lock nut. DO NOToverfighten.
• Removethe two bolts from the top of the motor unit.
• Placethe "U" bracket, flat side down onto the bolt mounted on
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.
Washer 5/8" (2)
HARDWARESHOWN ACTUALSIZE
o@
LockNut1/4"-20
Spacer
Bolt 1/4"-20x2-1/2" (1)
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.
To avoid SERIOUSdamageto garage door opener, use ONLY
those bolts/fasteners mounted in the top of the opener.
Hex Screws 8-32x7/16"_,
Bolts_ _ _L_Ohain
-____. [::_:._ Spreader
I
Bolt ___
Washer_
i
Spacer_
Cover
Protection
Bolt Hole
"U" Bracket
Motor Unit
Sprocket
SLIDE RAIL TO STOPS
ON TOP AND SIDES OF
1_ Lock Nut BRACKET
Chain and
Cable
Washer
Screwdriver
Trolley
Trolley
Stop Hole
Grease
_ _ _ _ -Inside Pulley
WasherL°Ck _ _ Idler Pulley
3/8" _, Nut 3/8"
Cable Link
Idler
Pulley
Bolt
Idler Bolt
HARDWARESHOWN ACTUALSIZE
Bolt 1/4"-20xl-3/4"
@
Lock Nut 1/4"-20
Nut 3/8"
Lock Washer 3/8"