Assembly; Attach The Rail To The Motor Unit; Set The Belt Tension - Chamberlain 3585CS Owner's Manual

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 rail, belt and styrofoam.
• REMOVE STYROFOAM.
• Position belt over the motor unit sprocket.
ASSEMBLY STEP 2

Set the Belt Tension

• By hand, thread the spring trolley nut on the threaded
shaft until it is fi nger tight against the trolley (Figure 1).
Do not use any tools.
• Insert a screwdriver tip into one of the nut ring slots
and brace it fi rmly against the trolley (Figure 2).
• Place a 7/16" open end wrench on the square end.
Rotate about 1/4 turn until the spring releases and
snaps the nut ring against the trolley (Figure 3).
This extends the spring for optimum belt tension.
Trolley
Nut Ring
BEFORE
1" (2.5 cm)
Figure 3
Trolley
Nut Ring
AFTER RELEASE
1-1/4" (3.18 cm)
To avoid SERIOUS damage to opener, ONLY use
bolts/fasteners mounted in top of motor unit.
USE ONLY THIS
TYPE AND SIZE
BOLT
Figure 1
Square End
Figure 2
6
Washered Bolt
Lock Nut
5/16"-18x1/2"
Rail Hole
Motor Unit Sprocket
Trolley Threaded Shaft
Spring/Trolley Nut
Trolley
Threaded
Shaft
Nut
Ring
Styrofoam
Nut Ring Slots