Chamberlain 3130M 1/3 HP - Manual (Page 6)

6
ASSEMBLY STEP 1
Fasten the Rail to the Motor Unit
To avoid installation diffi culties, do not run the garage
door opener until instructed to do so.
To aid in assembly and installation, replace the foam
packing around the motor unit. Remove it after Installation
Step 4.
• Working on a level surface, align the rail assembly with
the motor unit, as shown.
• Slip the coupling over the rail sprocket.
• Slide the rail through the motor unit bracket until the
coupling fi ts securely over the motor unit sprocket.
• Align the two bolt holes in the rail with those in the
motor unit bracket. Insert two 1/4"-20x7/16" hex bolts
and lock nuts. Tighten securely with a 3/8" socket
wrench.
• Turn release arm down to disengage trolley.
• Slide the trolley onto and along the bottom of the rail.
Align trolley with rack and turn release arm up to
re-engage trolley. Be certain to install it facing
correctly: the trolley release arm must be horizontal
(lock position).
Trolley
Rack
To motor unit
HARDWARE SHOWN ACTUAL SIZE
Foam Packaging
Motor Unit
Bracket
Motor Unit
Sprocket
Coupling
Rail Assembly
Rail Sprocket
Release Arm
Hex Bolts
1/4"-20x7/16"
Hex Bolt 1/4"-20x7/16"
Hex Bolts
1/4"-20x7/16"