Chamberlain ATS 211X 1/2 HP Owner's Manual page 19

INSTALLATION STEP 12
Connect Door Arm to Trolley
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 door) about 2" 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" 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.
• Proceed to Adjustment Step 1, page 20. 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"
Ring Fastener
Hex Bolt
5/16"-18x7/8"
19
Inner Trolley
Outer Trolley
Ring
Fastener
Door
Bracket
Clevis Pin
5/16"x1-1/4"
Figure 1
Lock
Washers
5/16"
Nuts
5/16"-18
Door Bracket
Figure 2
Lock
Washers
5/16"
Nuts
5/16"-18
Cut This End
Figure 3
Clevis Pin
5/16"x1"
Straight
Door Arm
Curved
Door Arm
Emergency
Release
Handle
Bolts
5/16"-18x7/8"
Bolts
5/16"-18x7/8"