Fastenthe Rail To The Motor Unit; Install The Idler Pulley - Craftsman 139.53939D Owner's Manual

ASSEMBLY STEP 2
Fastenthe Rail to the Motor Unit
• Insert a 1/4"-20xl-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. DONOTovertighten.
• Removethe two bolts from the top of the motor unit.
• Placethe "U" bracket, flat side down, on the motor unit and
align the bracket holes 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, aft the way to the stops that
protrude on the top and sides of the bracket.
To avoid SERIOUSdamageto garage door opener, use ONLY
those bolts/fasteners mounted in the top of the opener.
"U" Bracket
Bolt
I
Cover
Protection
Bolt Hole _
Bolts _ Motor Unit
Belt Pulley
HARDWARESHOWN ACTUALSIZE
Lock Nut
Bolt 1/4"-20xl-3/4" 1/4"-20
SLIDE RAIL TO STOPS
I
ON TOP AND SIDES
OF BRACKET
Lock Nut
ASSEMBLY STEP 3
Install the Idler Pulley
• Laythe belt beside the rail, as shown. Graspthe end with the
hooked trolley connector and pass approximately 12" (30 cm)
of belt through the window. Keepthe ribbed side toward the
rail, and 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.
Bolt
Trolley I _
Grease Stop Hole
_ _lnsidePulley _
- _ _ Idler Pulley
LockWasher3/8"@ Ill III _ _._
C)- Nut 3/8" i
Trolley
Connector _ Lock
Pulley _ Nut
Idler B_ _
HARDWARESHOWN ACTUALSIZE
Bolt U4"-20x]-3/4" LockNutU4"-20 Nut 3/8" Lock Washer 3/8"