Chamberlain B503C Manuel Du Propriétaire page 20

Installation
STEP 9 Connect the door arm to the trolley (continued)
OPTION B
ONE-PIECE DOORS
IMPORTANT: The groove on the straight door arm MUST face away from the curved door arm.
1. Close the door. Disconnect the trolley by pulling the emergency release handle.
2. Fasten the straight door arm and the curved door arm together to the longest possible length
(with a 2 or 3 hole overlap) using the bolts, nuts, and lock washers.
3. Attach the straight door arm to the door bracket using the clevis pin. Secure with the ring
fastener.
4. Attach the curved door arm to the trolley using the clevis pin. Secure with the ring fastener.
5. Pull the emergency release handle toward the garage door opener until the trolley release
arm is horizontal.
Clevis Pin 5/16"x1-1/4"
Ring Fastener
HARDWARE
Clevis Pin 5/16"x1"
Hex Bolt 5/16"-18x7/8"
Lock Washer
5/16" -18
Nut 5/16"-18
Straight Door Arm
(Groove facing out)
Curved Door Arm
One-Piece Door without Track
Ring Fastener
Lock Washer
Clevis Pin 5/16"x1-1/4"
One-Piece Door with Track
Ring Fastener
Lock Washer
Clevis Pin
5/16"x1-1/4"
20
Ring Fastener
Nut
Hex Bolts
Ring Fastener
Nut
Hex Bolts
Clevis Pin
5/16"x1"
Clevis Pin
5/16"x1"