Chamberlain HD175D 1/2 HP 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.
• 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.
HARDWARE SHOWN ACTUAL SIZE
Nut 5/16"-18 Lock Washer 5/16"
Clevis Pin
5/16"x1" (Trolley)
Ring Fastener
Clevis Pin Hex Bolt
5/16"x1-1/4" (Door Bracket) 5/16"-18x7/8"
Pulley
Trolley
Stop Bolt
Ring
Fastener
Door
Bracket
Clevis Pin
5/16"x1-1/4"
Figure 1
Pulley
Trolley
Stop Bolt
Nuts
5/16"-18
Door Bracket
Figure 2
Pulley
Trolley
Stop Bolt
Nuts
5/16"-18
Figure 3
25
Outer
Inner
Trolley
Trolley
Clevis Pin
5/16"x1"
Emergency
Release
Handle
Straight
Door Arm
Curved Door Arm
Lock
Washers
5/16"
Bolts
5/16"-18x7/8"
Lock
Washers
5/16"
Bolts
5/16"-18x7/8"
Cut this end