Assembly; Attach The Rail To The Motor Unit; Attach The Chain To The Sprocket - Chamberlain 3245C 3255 Owner's Manual

ASSEMBLY STEP 1

Attach the Rail to the Motor Unit

To avoid installation difficulties, do not run the
garage door opener until instructed to do so.
• Remove the two washered bolts mounted in top of
motor unit.
• Position rail at a 45˚ angle to opener so one hole
in rail and motor unit line up.
• Thread one of the washered bolts part way in.
Use only these bolts! Use of any other bolts will
cause serious damage to door opener.
• Align rail and styrofoam over sprocket. Cut tape
from rail, chain and styrofoam.
• REMOVE STYROFOAM.
ASSEMBLY STEP 2

Attach the Chain to the Sprocket

and Install the Sprocket Cover
• Position chain over the sprocket. If necessary,
loosen the outer nut on the trolley to obtain more
chain slack.
• Insert the second washered bolt. CAUTION: Use
only the bolt previously removed from motor
unit!
• Tighten both bolts securely through the rail into the
motor unit as shown.
• Install the sprocket cover: Insert the back tab in the
slot. Squeeze the cover slightly and insert the front
tab in the slot on the mounting plate.
WARNING
CAUTION
To avoid SERIOUS damage to garage door opener,
use ONLY those bolts/fasteners mounted in the top of
the opener.
USE ONLY THIS
TYPE AND SIZE
BOLT
WARNING
To avoid possible SERIOUS INJURY to fingers from
moving garage door opener:
CAUTION
• ALWAYS keep hand clear of sprocket while operating
opener.
• Securely attach sprocket cover BEFORE operating.
USE ONLY THIS
TYPE AND SIZE
BOLT
Sprocket Cover
Front Tab Slot
Mounting
Plate
6
Washered Bolt
5/16"-18x1/2"
Styrofoam
Rail
Hole
Washered Bolts
5/16"-18x1/2"
Sprocket
Back Tab Slot