Chamberlain 3575S - Manual (Page 6)

Washered Bolt
5/16"-18x1/2"
Styrofoam
T-rail
Hole
Lock Nut
6
ASSEMBLY STEP 1
Attach the T-Rail to the Motor Unit
To avoid installation difficulties, 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 fingers from moving
garage door opener:
• ALWAYS keep hand clear of sprocket while operating opener.
• Securely attach chain spreader BEFORE operating.
Chain
Spreader
Motor Unit
Sprocket
Hex Screws
8-32x7/16
Chain
Spreader
Motor Unit
Sprocket
To avoid SERIOUS damage to garage door opener, use ONLY
those bolts/fasteners mounted in the top of the opener.