Chamberlain 3275 Garage Door Opener User Manual


 
6
ASSEMBLY STEP 1
Attach the Rail to the Motor Unit
To avoid installation diffi culties, do not run the garage
door opener until instructed to do so.
Remove the bolt and lock nut from the top of the motor
unit.
Place rail onto the bolt mounted on the motor unit and
align the back hole with the hole in the top of the unit.
Fasten rail with the washered bolt and lock nut
previously removed. Tighten securely. Remember
to use only these bolts/fasteners! Any other bolts/
fasteners will cause serious damage to the opener.
Cut tape from T-rail, chain and styrofoam.
• REMOVE STYROFOAM.
ASSEMBLY STEP 2
Attach the Chain Spreader
Attach chain spreader to the motor unit with two
screws.
Position chain over chain spreader and into the slot
of the spreader. Wrap chain around the sprocket. If
necessary, loosen the outer nut on the trolley to obtain
more chain slack.
To avoid possible SERIOUS INJURY to fi ngers from
moving garage door opener:
• ALWAYS keep hand clear of sprocket while operating
opener.
• Securely attach chain spreader BEFORE operating.
To avoid SERIOUS damage to garage door opener, use
ONLY those bolts/fasteners mounted in the top of the
opener.
Washered Bolt
5/16"-18x1/2"
Styrofoam
Lock Nut
T-Rail Hole
Chain
Spreader
Chain
Spreader
Motor Unit
Sprocket
Motor Unit
Sprocket
Hex Screws
8-32x7/16"