Chamberlain Power Drive Security+ HD400DM Owner's Manual page 25

INSTALLATION STEP 12
Connect Door Arm to Trolley
Follow instructions which apply to your door type as
illustrated below and on the following page.
SECTIONAL DOORS ONLY
• Make sure garage door is fully closed. Pull the
emergency release handle to disconnect the outer
trolley from the inner trolley. Slide the outer trolley back
(away from the pulley) about 8" (20 cm) as shown in
Figures 1, 2 and 3.
• Figure 1:
– Fasten straight door arm section to outer trolley
with the 5/16"x1" clevis pin. Secure the connection
with a ring fastener.
– Fasten curved section to the door bracket in the
same way, using the 5/16"x1-1/4" clevis pin.
IMPORTANT: The groove on the straight door arm MUST
face away from the curved door arm (Figure 4).
• Figure 2:
– Bring arm sections together. Find two pairs of holes
that line up and join sections. Select holes as far
apart as possible to increase door arm rigidity.
• Figure 3, Hole alignment alternative:
– If holes in curved arm are above holes in straight
arm, disconnect straight arm. Cut about 6" (15 cm)
from the solid end. Reconnect to trolley with cut
end down as shown.
– Bring arm sections together.
– Find two pairs of holes that line up and join with
bolts, lock washers and nuts.
• Pull the emergency release handle toward the opener at
a 45° angle so that the trolley release arm is horizontal.
Proceed to Adjustment Step 1, page 27. Trolley will
re-engage automatically when opener is operated.
Nut 5/16"-18 Ring Fastener
Clevis Pin 5/16"x1-1/4"
(Door Bracket)
Clevis Pin 5/16"x1"
(Trolley)
HARDWARE SHOWN
ACTUAL SIZE
Lock Washer 5/16"
Hex Bolt
5/16"-18x7/8"
Figure 1
Pulley
Trolley
Stop Bolt
Ring
Fastener
Door
Bracket
Clevis Pin
5/16"x1-1/4"
Figure 2
Pulley
Trolley
Stop Bolt
Lock
Washers
5/16"
Nuts
5/16"-18
Door Bracket
Figure 3
Pulley
Trolley
Stop Bolt
Lock
Washers
Nuts
5/16"
5/16"-18
Cut this end
Figure 4
CORRECT
Straight
Door Arm
Curved
Door
(Groove
Arm
facing out)
25
Outer
Trolley
Inner
Clevis Pin
Trolley
5/16"x1"
Emergency
Release
Handle
Straight
Door Arm
Curved
Door Arm
Bolts
5/16"-18x7/8"
Bolts
5/16"-18x7/8"
INCORRECT
Straight
Door Arm
Curved
Door
Arm