Craftsman 1/2 HP GARAGE DOOR OPENER 139.53978SRT - Manual (Page 12)

Installation Section: Pages 12-27
Installation Step 1
Determine Header Bracket Location
Installation procedures vary according to
garage door types. Follow the instructions
which appiy to your door.
OiiE-PIECE Ooof WÎÏN mck
Vertical
Guideline
Finished
Ceiling
Structural
.Supports
It the header bracket is not rigidly fastened to
a structural support on the header wall or
ceiling, the safety reverse system may not
work properly (see page 30).
The door might
not reverse when required, and could cause
serious injury or death.
The garage door springs, cables, pulleys,
brackets and their hardware are under extreme
tension.
Do not attempt to loosen, move or
adjust them yourself. Serious persona! injury
or death could result.
Cail for professionai
garage door service.
• Close the door and mark the inside
verticai centerline of the garage door.
• Extend the line onto the header wall
above the door.
Remember, you can fasten the
header bracket within 2 feet of the
left or right of the door center o/r/y if
a torsion spring or center bearing
plate is in the way; or you can attach
it to the ceiiing (refer to page 14)
when ciearance is minimal. (It may
be mounted on the wall upside down
if necessary, to gain approximately
1/2".)
if you need to install the header bracket
on a 2x4 (on wall or ceiling), use tag
screws (not provided) to securely fasten
the 2x4 to structural supports as shown
here and on page 13.
• Open your door to the highest
point of travel as shown. Draw
an intersecting horizontal line
on the header wall 2“ above
the high point. This height will
provide travel clearance for the
top edge of the door.
Door clearance brackets are
available for sectional doors
when headroom clearance is
less than 2". See accessory
page 38.
Ceiling
Ooor
Header
_Wall
— 2 " Track
Highest Point
of Travel
Track
Proceed to Step 2, page 14.
Sectional door
with curved track
One-piece door
with horizontal track
12