Chamberlain WHISPER DRIVE 248754 - Manual (Page 28)

28
ALL ONE-PIECE DOORS
1. Assemble the Door Arm
IMPORTANT: The groove on the straight door arm MUST
face away from the curved door arm (Figure 5).
• Fasten the straight and curved door arm sections
together to the longest possible length (with a 2 or 3
hole overlap) (Figure 5).
• Make sure the garage door is fully closed. Connect the
straight door arm section to the door bracket with the
5/16"x1-1/4" clevis pin.
• Secure with a ring fastener.
• Pull the emergency release handle, disconnecting the
outer trolley from the inner trolley by pulling straight
down on the emergency release handle and sliding the
outer trolley back toward the motor unit.
• Connect the curved door arm section to the trolley
using the 5/16"x1-1/4" clevis pin and ring fastener.
NOTE: Adjusting the limits on the following page:
• The trolley will automatically connect. If not, review
the trolley lockout feature on page 34.
• When setting the up limit on the following page, the
door should not have a “backward” slant when fully
open as illustrated below. A slight backward slant will
cause unnecessary bucking and/or jerking operation
as the door is being opened or closed from the fully
open position (Figure 6).
Figure 5
Figure 6
Straight
Door
Arm
Curved
Door
Arm
(Groove
facing out)
Straight
Door
Arm
Door
Bracket
Straight
Arm
Bolts
5/16"-18x7/8
Curved
Door Arm
Door Arm
Inner Trolley
Inner Trolley
Outer Trolley
Outer Trolley
Emergency
Release Handle
Closed
Door
Open Door
Correct Angle
Door with Backward Slant (Incorrect)
Lock
Washers
5/16" Nuts
5/16"-18
Ring
Fastener
Curved
Door
Arm
CORRECT INCORRECT
Clevis Pin
5/16"x1-1/4"