Install The Idler Pulley - Craftsman 139.53985DM Owner's Manual

ASSEMBLY STEP 2
Fasten the Rail to the Motor Unit
1. 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.
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, flat side down onto the motor
unit and align the bracket hole with the bolt holes.
Fasten the "U" bracket with the previously removed
bolts, hand tighten ONLY and DO NOT use any power
tools. The use of power tools may permanently
damage the garage door opener.
5. Attach spreader to the motor unit with two screws.
To avoid SERIOUSdamageto garage door opener, use ONLY
those b01ts/fastenersmounted in the top of the opener.
Bolt
1/4" 20x2 1/2
x'_ Bolts
"U" Bracket
Washer 5/8"
Spacer
Hex Screws
8 32X7/16" "_-'_'t_
I
Cover
Protection
Bolt Hole
Chain
>reader
0
Lock Nut 1/4"-20
HARDWARE SHOWN ACTUAL SIZE
Washer 8/8" Spacer
Bolt 1/4"-20x2-1/2
Spacer
I
Washer
5/8 "_
I
lock Nut _
1/4" 20
ASSEMBLY STEP 3
Install the Idler PuUey
1. Lay the chain/cable beside the rail, as shown. Grasp
the end of the cable and pass approximately 12"
(30 cm) of cable through the window. 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°).
Chain and
Cable
._ Grease
-. __lnside Pulley
Lock i _ Idler
Washer _ Pulley
3/8"
_i Nut 3/8"
Cable Link
CORRECT
iNCORRECT
Q
Idler Bolt
HARDWARE SHOWN ACTUAL SIZE
Nut 3/8"
Lock Washer 3/8"