Chamberlain WHISPER DRIVE HD900D - Manual (Page 14)

14
INSTALLATION STEP 3
Attach the Rail to the Header Bracket
NOTE: (Optional) With some existing installations, you may
re-use the old header bracket with the two plastic spacers
included in the hardware bag. Place the spacers inside the bracket
on each side of the rail, as illustrated.
• Position the opener on the garage floor below the header
bracket. Use packing material as a protective base.
NOTE: If the door spring is in the way you’ll need help. Have
someone hold the opener securely on a temporary support to
allow the rail to clear the spring.
• Position the rail bracket against the header bracket.
• Align the bracket holes and join with a clevis pin as shown.
• Insert a ring fastener to secure.
Opener Carton or
Temporary
Support
OPTION WITH
SOME EXISTING
INSTALLATIONS
Garage
Door
Header Bracket
Idler Pulley
Header Wall
Header
Bracket
Mounting
Hole
Existing
Header Bracket
Spacer
Mounting
Hole
Existing
Clevis Pin
Clevis Pin 5/16"x1-1/2" Ring Fastener
HARDWARE SHOWN ACTUAL SIZE