Assembly Pages; Attach The Rail To The Motor Unit; Set The Belt Tension - Chamberlain 2585 3 HP 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 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 finger 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 firmly 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"
Figure 3
Trolley
Nut Ring
AFTER RELEASE
1-1/4"
WARNING
CAUTION
To avoid SERIOUS damage to opener, ONLY use
bolts/fasteners mounted in top of motor unit.
Rail
Hole
Spring/Trolley Nut
Figure 1
Figure 2
6
Washered Bolt
5/16"-18x1/2"
Lock Nut
Styrofoam
Trolley
Threaded
Shaft
Trolley
Threaded
Shaft
Nut
Ring
Square
End
Nut Ring
Slots