Chamberlain B353 Guide De L'utilisateur page 9

Installation
For sectional door installations, see Installation step 11 in the Installation Manual.
Installation 11 - Connect the Door Arm to the Trolley
One-Piece Door Only
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.
To continue, go to Installation step 14 in the
Installation Manual
PP QQ
Clevis Pin 5/16"x1-1/4" Clevis Pin 5/16"x1"
KK
Ring Fastener
HARDWARE
LL
Hex Bolt
MM NN
Lock Washer Nut
Straight Door Arm
(Groove facing out)
Curved Door Arm
One-Piece Door without Track
KK
NN
MM
L
PP
One-Piece Door with Track
KK
NN
MM
L
PP
9
KK
M
QQ
LL
1/2"
KK
M
QQ
1/2"
LL