Chamberlain 248739 Garage Door Opener User Manual


 
ASSEMBLY STEP 4
Install the Belt and Attach the Belt Cap
Retainer
1. Pull the belt around the idler pulley and toward the
trolley. The ribbed side must contact the pulley.
2. Hook the trolley connector into the retaining slot on the
trolley as shown.
3. With the trolley against the screwdriver, dispense the
remainder of the belt along the rail length toward the
motor unit and around the sprocket. The sprocket teeth
must engage the belt.
4. Check to make sure the belt is not twisted and the
FLAT side of the trolley threaded shaft is facing the rail.
Connect the trolley threaded shaft with the master link,
as illustrated:
Push pins of master link bar through holes in end of
belt and trolley threaded shaft.
Push master link cap over pins and past pin notches.
Slide clip-on spring over cap and onto pin notches
until both pins are securely locked in place.
5. Insert the trolley threaded shaft through the hole in the
trolley. Be sure the belt is not twisted and the FLAT
side of the trolley threaded shaft faces the rail.
6. Hold the belt at the trolley shaft as you thread the
spring nut by hand onto the shaft until finger tight
against the trolley. Do not use any tools.
7. Remove the screwdriver.
8. Position the belt cap retainer over the motor unit
sprocket as shown and fasten to the mounting plate
with 8x3/8" hex screws provided.
To avoid possible SERIOUS INJURY to fingers from moving
garage door opener:
ALWAYS keep hand clear of sprocket while operating opener.
Securely attach sprocket cover BEFORE operating.
WARNING
CAUTION
WARNING
WARNING
Trolley
Connector
Idler Pulley
Retaining
Slot
Round
Hole
Master Link
Clip-On Spring
Master Link Cap
Trolley
Threaded
Shaft
Master
Link Bar
Pin
Notch
Hex Screw 8x3/8"
HARDWARE SHOWN ACTUAL SIZE
Spring/Trolley Nut
Spring Nut
Motor Unit
Sprocket
Mounting
Plate
Hex Screws
#8x3/8"
Belt Cap
Retainer
Trolley
Connector
Idler Pulley
Retaining
Slot
Hole
Master Link
Clip-On Spring
Master Link Cap
Trolley
Threaded
Shaft
Master
Link Bar
Pin
Notch
10