Chamberlain 8100M User manual

The Chamberlain Group, Inc.
A DUCHOSSOIS ENTERPRISE
845 Larch Avenue
Elmhurst, Illinois 60126-1196
Complies with UL 325
Regulations effective
January 1, 1993. ®
Garage Door Opener
Model 8100M
1/2 HP
For Residential Use Only
Owner's Manual
■Please read this manual and the enclosed safety materials carefully!
■Fasten the manual near the garage door after installation.
■The door WILL NOT CLOSE unless the Protector System®is connected and
properly aligned.
■Periodic checks of the opener are required to ensure safe operation.
■The model number label is located under the light lens on the side panel of
your opener.

Start by reviewing these important safety alert symbols
2
Contents Page
A review of safety alert symbols..................................2
You'll need tools...........................................................3
Safety information regarding garage door
locks and ropes..........................................................3
Testing your garage door for sticking,
binding and balance...................................................3
Illustration of sectional door installation ......................4
Illustration of one-piece door installation.....................5
Carton inventory...........................................................6
Hardware inventory......................................................7
Assembly section – pages 8 - 11
Assemble T-rail..........................................................8
Attach belt pulley bracket ..........................................8
Install trolley...............................................................9
Fasten T-rail to opener ..............................................9
Install belt.................................................................10
Set the belt tension..................................................10
Attach belt cap retainer............................................11
Installation section – pages 11 - 27
Installation safety instructions..................................11
Determine header bracket location
Sectional door........................................................12
One-piece door......................................................13
Install the header bracket........................................14
Attach the T-rail to header bracket..........................15
Position the opener..................................................16
Hang the opener......................................................17
Install the multi-function door control panel ............18
Contents Page
Install the lights and lenses......................................19
Attach manual release rope and handle..................19
Electrical requirements.............................................20
The Protector System®.............................................21
Install the safety reversing sensor.....................22, 23
Fasten door bracket (sectional door).......................24
Fasten door bracket (one-piece door).....................25
Connect door arm to trolley (sectional door) ...........26
Connect door arm to trolley (one-piece door)..........27
Adjustment section – pages 28 - 30
Travel limit adjustments ...........................................28
Force adjustments....................................................29
Test the Protector System®......................................30
Test the safety reverse system ...............................30
Operation safety instructions .....................................31
Care of your opener ...................................................31
Maintenance schedule...............................................31
Operation of your opener...........................................32
Receiver and remote control programming...............33
Having a problem?...............................................34, 35
Repair parts, rail assembly.........................................36
Repair parts, installation.............................................36
Repair parts, opener assembly..................................37
Accessories................................................................38
Index...........................................................................39
How to order repair parts ...........................................40
Warranty.....................................................................40
When you see these Safety Symbols on the following pages, they will alert you to the possibility of
serious injury or death if you do not comply with the corresponding instructions. The hazard may
come from something mechanical or from electric shock. Read the instructions carefully.
When you see this Safety Symbol on the following pages, it will alert you to the possibility of damage
to your garage door and/or the garage door opener if you do not comply with the corresponding
instructions. Read the instructions carefully.
This garage door opener is designed and tested to offer safe service provided it is installed, operated,
maintained and tested in strict accordance with the safety instructions contained in this manual.
Mechanical Electrical
WARNING WARNING
CAUTION

Pliers
Wire Cutters
Claw Hammer
Hack Saw
Screwdriver Adjustable End Wrench
1/2" and 7/16" Sockets
and Wrench
Drill
Tape Measure
2
1
Stepladder
Pencil
3/16", 5/16" and
5/32" Drill Bits
Carpenter's
Level
You'll Need Tools
During assembly, installation and adjustment of the opener, instructions will call for hand tools shown below.
SECTIONAL DOOR ONE-PIECE DOOR
3
An unbalanced garage door might not reverse
when required and someone under the door
could be seriously injured or killed.
If your garage door binds, sticks or is out of
balance, call for professional garage door
service. Garage doors, door springs, cables,
pulleys, brackets and their hardware are under
extreme tension and can cause serious injury
or death. Do not try to loosen, move or adjust
them yourself!
Ropes left on a garage door could cause
someone to become entangled and killed.
Remove all ropes connected to the door before
installing and operating the opener.
To avoid damage to the garage door and
opener, disable locks before installing and
operating the opener. Use a wood screw or nail
to hold locks in the "open" (unlocked)
position.
Operation at other than 120V 60 Hz will cause
opener malfunction and damage.
Identify the type and height of your door and any
special conditions that exist and any additional
materials that may be required.
WARNING CAUTION
Before you begin, complete the following test to
make sure your door is balanced, and is not
sticking or binding:
• Lift the door about halfway as shown. Release the
door. It should stay in place, supported entirely by
its springs.
• Raise and lower the door to see if there is any
binding or sticking.

4
Safety Reversing Sensor
Horizontal and vertical reinforcement
is needed for lightweight garage doors
(fiberglass, steel, aluminum, door with glass panels, etc.).
See page 24 for details.
Support bracket &
fastening hardware
is required.
See page 17.
— — — — — — — —
Door Center
Header Wall
Safety
Reversing
Sensor
Floor must be level
across width of door
FINISHED CEILING
Extension Spring
Torsion Spring
Access Door
OR
Slack in belt tension
is normal when
garage door is closed.
Before you begin, survey your garage area to
see whether any of the conditions below apply
to your installation.
Based on your particular requirements, there are
several installation steps which might call for
materials and/or hardware not included in the
carton.
• Step 1, page 12 - Look at the wall or ceiling above
the garage door. The header bracket must be
securely fastened to structural supports.
• Step 5, page 17 - Do you have a finished ceiling in
your garage? If so, a support bracket and
additional fastening hardware may be required.
• Safety reversing sensor, page 21 - Depending
upon garage construction, wood blocks may need
to be fastened to mounting locations before
sensors are installed.
• Step 10, page 22 - Alternate floor mounting of the
safety reversing sensor will require hardware not
provided.
• Step 11, page 24 - Do you have a steel, aluminum,
fiberglass or glass panel door? If so, horizontal
and vertical reinforcement is required.
• Look at the garage door where it meets the floor.
It must close on the floor all the way across.
Otherwise, the safety reverse system may not
work properly. See page 30. Floor or door should
be repaired.
• If your door is more than 7 feet high, see longer
rails available on page 38.
SECTIONAL Door Installation
• The opener can be installed within 2 feet of the left
or right of the door center if there is a torsion spring
or center bearing plate in the way of the header
bracket or door bracket area. If your door has
extension springs, the opener must be installed
in the center of the door. See pages 12 and 24.
• Do you have an access door in addition to the
garage door? If not, Model 7702CB Outside Quick
Release is required. See page 38.
You may find it helpful to refer back to this page
as you proceed with the installation of your
opener.
Belt Pulley
Bracket
Header
Bracket Trolley
Straight
Door
Arm Manual
Release
Rope & Handle
Door Bracket
Garage
Door
Curved
Door
Arm
Garage
Door
Spring
Header
Wall
Closed Position
Belt

Safety
Reversing Sensor
FINISHED CEILING
Support bracket
& fastening
hardware is required.
See page 17.
Slack in Belt Tension
is Normal When
Garage Door is Closed
Safety
Reversing
Sensor
Header
Wall
Access Door
Gap between floor and bottom
of door must not exceed 1/4".
5
Closed Position
Belt
Pulley Bracket
Header
Bracket
Trolley
Straight
Door
Arm
Manual
Release
Rope & Handle
Door
Bracket
Curved
Door
Arm
Header
Wall
Belt
T-rail
Garage
Door
Before you begin, survey your garage area to
see whether any of the conditions below apply
to your installation.
Based on your particular requirements, there are
several installation steps which might call for
materials and/or hardware not included in the
carton.
• Step 1, page 13 - Look at the wall or ceiling above
the garage door. The header bracket must be
securely fastened to structural supports.
• Step 5, page 17 - Do you have a finished ceiling in
your garage? If so, a support bracket and additional
fastening hardware (not supplied) may be required.
• Safety reversing sensor, page 21 - Depending on
garage construction, wood blocks may need to be
securely fastened to mounting locations before
sensors are installed.
• Step 10, page 22 - Alternate floor mounting of the
safety reversing sensor will require hardware that
is not provided.
• Step 11, page 25 - Generally, a one-piece door
does not require reinforcement. If your door is
lightweight, you can refer to the information
relating to sectional doors on page 24.
• Step 11, page 25 - Depending on your door's
construction, you might need additional mounting
hardware for the door bracket.
• Do you have an access door in addition to the
garage door? If not, Model 7702CB Outside Quick
Release is required. See page 38.
• The gap between the bottom of the garage
door and the floor cannot exceed 1/4".
Otherwise, the safety reverse system may not
work properly. See page 30. The floor or the door
should be repaired.
ONE-PIECE Door Installation
You may find it helpful to refer back to this page
as you proceed with the installation of your
opener.
One-Piece Door without Track
Access
Door
Floor must be level
across width of door
Safety
Reversing
Sensor
Safety
Reversing
Sensor
Slack in Belt Tension
is Normal When
Garage Door is Closed
One-Piece Door with Track
Closed Position
Header
Bracket
Belt
Pulley Bracket
Door
Bracket
Straight
Door
Arm
Curved
Door Arm
Trolley
Manual Release
Rope & Handle
Header
Wall
T-rail
Garage
Door
Belt

Multi-Function
Remote Control Transmitter 2-Conductor Bell Wire
White & White/Red
Trolley Door Bracket
Door Bracket
Plate
Header Bracket
Hanging Brackets
Belt
Curved Door
Arm Section
Straight Door
Arm Section
Safety Labels
and
Literature
Safety Reversing Sensor
Mounting Bracket
With Square Holes (2)
"C" Wrap (2)
Safety Reversing Sensor
Mounting Bracket
With Slot (2)
Light Lens
Rail Brace (3)
T-rail
Center Section
(each) (2)
T-rail
End Section (2)
UP
CEILING MOUNT ONLY
LIGHT
LOCK
Multi-Function
Door Control Panel
Belt Pulley
Bracket
Belt Cap Retainer
Keyless Entry
(2) Safety Reversing Sensors
(1 Sending Eye and 1 Receiving Eye)
with
2-Conductor White & White/Black Bell Wire
attached
6
Opener Carton Inventory
Your garage door opener is packaged in one carton which contains all parts illustrated below. If anything is
missing, carefully check the packing material. Parts may be "stuck" in the foam. Hardware for assembly and
installation is shown on page 7.

Lock Washer
5/16" (4)
Nut 5/16"-18 (6)
Clevis Pin
5/16"x2-3/4" (1)
NOTICE
Handle
Insulated
Staples (10)
Assembly Hardware
Installation Hardware
Dry Wall Anchors (2)
Clevis Pin
5/16"x1" (1)
Hex Screw
5/16"-18x7/8" (4)
Rope
Trolley Clip (1)
Lock Nut
1/4"-20x7/16" (12)
Nut
5/16"-18 (4)
Washered Screw
5/16"-18x1/2" (2)
(mounted in opener)
Carriage Bolt
5/16"-18x2-1/2" (2)
Carriage Bolt
1/4"-20x1/2" (12) Master Link (2)
Ring 
Fastener (3)
7
Trolley
Threaded Shaft (1)
Screw
6ABx1" (2)
Lock Washer 5/16" (6)
Lag Screw
5/16"-9x1-5/8" (2)
Lock Nut
1/4"-20 (4)
Carriage Bolt
1/4"-20x1/2" (4)
Safety Reversing Sensor
Installation Hardware
Hex Screw
1/4-20x1-1/2" (2) Screw
#10-32x3/8" (4) Lock Nut
#10x32 (4)
Wing Nut (2)
Insulated
Staples (20)
RAIL GREASE
NO. 83A4
Rail Grease
Hex Screw
5/16"-18x7/8" (4)
Lag Screw
1/4x1-1/2" (4)
Spring Nut (1)
Lag Screw
5/16"-18x1-7/8" (2)
Clevis Pin
5/16"x1-1/4" (1)
7
Group all hardware found in all packages contained in the rail and opener cartons into
the three kits illustrated below.

8
Assembly Step 1
Assemble the T-rail &
Attach the Belt Pulley Bracket
T-RAIL BACK
(TO OPENER)
T-RAIL FRONT
(TO DOOR)
Belt pulley bracket
attaches to FRONT
END of T-rail T-rail
(End Section)
T-rail
(Center Section)
Carriage Bolt
1/4"-20x1/2"
T-rail
(End Section)
Square Carriage
Bolt Hole
1/4" Lock Nut
y
Bracket
Bracket & Rail Must Be Aligned
Lock Washer
5/16"
Nut
5/16"-18
Hex Screws
5/16"-18x7/8"
Belt Pulley
Bracket
Bracket & Rail Must Be Aligned
Lock Washer
5/16"
Nut
5/16"-18
Make sure bolt
necks are
seated in the
square holes
and rails are
aligned before
you tighten lock
nuts. (See right
and wrong
views).
Improper
assembly can
cause jerky
trolley
operation, noise
and/or nuisance
door reversals.
To avoid installation difficulties, do not run the garage door opener until instructed to do so.
Assembly Section: Pages 8 – 11
When tightening
the screws, be
sure to keep
bracket parallel
to the rail.
Otherwise, the
rail may bow
when the opener
is operated.
Right Wrong
• Align the 4 T-rail sections on a flat surface
exactly as shown. Center sections are
interchangeable. Front and back sections are
also interchangeable for ease of assembly.
• Insert the carriage bolts so the square bolt
necks seat in the square holes in the T-rail
sections and pass through the round holes in
the rail braces. Assemble lock nuts, ensure
alignment and tighten.
If T-rail is not assembled
exactly as shown, trolley
will not travel smoothly
along length of rail or it
will hit against nuts.
• Position the belt pulley bracket on the front end of
the T-rail as shown. Fasten securely with the
hardware shown.
Right
Wrong
Lock Nut
1/4"-20x7/16" Carriage Bolt
1/4"-20x1/2"
Hex Screw
5/16"-18x7/8"

Nut
5/16"-18 Lock Washer
5/16"
Hardware Shown Actual Size

Assembly Step 2
Install the Trolley on the T-rail
9
• As a temporary stop, insert a screwdriver into the
hole in the front end of the T-rail.
• Slide the trolley assembly along the rail to the
screwdriver stop.
If trolley hits against any nuts on the T-rail, the
bolts and nuts were attached from the wrong
side and must be repositioned. Review Step 1.
• Insert a 5/16"-18x7/8" hex screw into the trolley
stop hole in the T-rail as shown. Tighten securely
with a 5/16" lock washer and nut. This screw limits
trolley travel in the DOWN direction.
Temporary Stop
Screwdriver
Trolley
Hex Screws
# 8 x 3/8" BltC
Assembly Step 3
Faster the T-rail to the Opener
• Place the opener on packing material to protect
the cover. For convenience, put a support under
the belt pulley bracket.
• Remove the (2) 5/16"-18x1/2" washered screws
mounted in the top of the opener.
• Align the holes in the back section of the T-rail with
the holes in the opener.
• Fasten the rail with the (2) washered screws
previously removed. Tighten securely.
Remember to use only these screws! Any other
screws will cause serious damage to the opener.
• Insert a 5/16"-18x7/8" hex screw into the trolley
stop hole in the T-rail as shown. Tighten securely
with a 5/16" lock washer and nut. This screw limits
trolley travel in the UP direction.
Washered Screw
5/16"-18x1/2" USE ONLY THIS
TYPE AND SIZE
SCREW
T-Rail
(Back Section)
Trolley
Stop Hole
Nut
5/16"-18
Hex Screw
5/16"-18x7/8"
Lock Washer
5/16"
To fasten rail, use only those screws mounted
in the top of the opener. Any other screws will
cause serious damage to the opener.
Lock Nut
1/4"-20x7/16" Carriage Bolt
1/4"-20x1/2"
Hex Screw
5/16"-18x7/8"

Nut
5/16"-18 Lock Washer
5/16"
Hardware Shown Actual Size
CAUTION
Hex Screw
5/16"-18x7/8"
Trolley
Stop Hole
Lock Washer
5/16"
Nut
5/16"-18

Assembly Step 4
Install the Belt & Set the Belt Tension
Serious injury can result if fingers become
entangled in moving opener sprocket. Attach
belt cap retainer securely. Never operate
opener while your hand is near the opener
sprocket.
The Chamberlain Group, Inc.
Liftmaster Synchro Drive
Spring Trolley Nut Assembly
3/5/92 - 5/16 /92 - 5/21/92 - 6/2/92
6/11/92
Nut
Ring
Trolley
Threaded 
Shaft
Nut Ring
Slots
Trolley
Square End
The Chamberlain Group, Inc.
Attach Tee Rail To Opener Chassis
Liftmaster Synchro Drive GDO (Belt)
3/13/92 - 6/2/92 - 6/3/92
Opener
Sprocket
Hex Screws
8x3/8" Belt Cap
Retainer
Opener Sprocket
Mounting Plate
Belt
Hex Screw
8x3/8"
Opener Sprocket
10
•Drop the notched side of the trolley clip into the
retaining slot on top of the trolley (see Figure 1).
• Grasp the clip connector at the end of
the belt and slip it through the belt
pulley bracket from behind, around
the pulley and toward the trolley.
• Fasten the belt clip connector to the
trolley clip with a master link:
a. Push pins of master link bar through holes in
trolley clip and belt clip connector.
b. Push master link cap over pins and
past pin notches.
c. Slide clip-on spring over cap and onto
pin notches until both pins are
securely locked in place.
• With the trolley against the screwdriver,
dispense the belt along the rail and around
the opener sprocket. The sprocket teeth
must engage the belt (Figure 2).
• Use the second master link to connect the belt to
the flat end of the trolley threaded shaft (Figure 1).
Check to make sure the belt is not twisted.
•Remove the screwdriver.
Belt
Pulley
Slip Belt Clip 
Connector
through 
Pulley Bracket
from this direction
and attach 
to trolley clip
Trolley
Clip
Master Link
Clip-On Spring Master
Link Cap
Trolley
Threaded Shaft
Master
Link Bar
Pin 
Notch
Pin 
Notch
Belt
Clip Connector
Figure 2
Figure 1
Figure 4
WARNING
CAUTION
WARNING
• Insert a screwdriver tip into one of the nut ring slots
and brace it firmly against the trolley. (Figure 4)
• Place a 7/16" open end wrench on the square end.
Rotate about 1/4 turn until the spring releases and
snaps the nut ring against the trolley (Figure 5).
This extends the spring for optimum belt tension.
• Insert the trolley threaded shaft through the hole in
the trolley.
• Hold the belt at the trolley shaft to avoid twisting
as you thread the spring/trolley nut by hand on the
shaft until finger tight against the trolley (Figure 3).
Do not use any tools.
Belt Clip 
Connector
Belt Clip 
Connector
The Chamberlain Group, Inc.
Liftmaster Synchro Drive
Spring Trolley Nut Assembly
3/5/92 - 5/16 /92 - 5/21/92 - 6/2/92
6/11/92
Trolley
Threaded
Shaft
Spring
Trolley Nut
Trolley
The Chamberlain Group, Inc.
Spring Trolley Nut
1/25/96
Nut Ring Trolley Nut Ring Trolley
1" 1-1/4"
BEFORE AFTER RELEASE
Figure 5Figure 3

Hex Screws
#8x3/8" Belt Cap
Retainer
Opener Sprocket
Mounting Plate
Belt
Assembly Step 5
Attach the Belt Cap Retainer
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of severe injury or death to persons:
1. READ AND FOLLOW ALL INSTALLATION INSTRUCTIONS.
2. Install only on a properly balanced and lubricated garage door. An improperly balanced door
may not reverse and could result in severe injury or death. Repairs to cables, spring assemblies
and other hardware must be made by a professional service person before installing opener.
3. Disable all locks and remove all ropes connected to the garage door before installing the opener.
Ropes connected to a garage door can cause entanglement and death.
4. If possible, install door opener 7 feet or more above floor with the manual release handle
mounted 6 feet above the floor.
5. Do not connect the opener to power source until instructed to do so.
6. Locate the Door Control within sight of the door at a minimum height of 5 feet where small
children cannot reach and away from all moving parts of the door.
7. Install the User Safety Instruction Label on the wall adjacent to the control button and the
Maintenance Instruction Label in a prominent location on the inside of the garage door.
8. Upon completion of the installation, the door must reverse when it comes in contact with a
one-inch high object (or a 2x4 laid flat) on the floor.
9. Do not wear watches, rings or loose clothing while installing or servicing an opener. Jewelry or
loose clothing can be caught in the mechanism of the garage door or the opener.
11
You have now finished assembling your garage door opener. Please read the following
warnings before proceeding to the installation section:
WARNING WARNING
To attach the belt cap retainer:
• Position the belt cap retainer over the opener
sprocket so the two holes in cap align with the two
holes in mounting plate. Attach with 8x3/8" hex
screws provided.
Hex Screw
#8x3/8"
Hardware Shown
Actual Size

• 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.
Header
Wall
Ceiling
Track
Highest Point
of Travel
Door
2"
12
Proceed to Step 2, page 14.
Door
Track
Header
Wall
Highest Point
of Travel
2"
Vertical
Guideline
Finished
Ceiling
Vertical
Guideline
Header
Wall 2x4 Structural
Supports
SECTIONAL Door and
ONE-PIECE Door With Track
• Close the door and mark the inside
vertical 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 to the
left or right of the door center only if
a torsion spring or center bearing
plate is in the way; or you can attach
it to the ceiling (refer to page 14)
when clearance 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 lag
Installation Section: Pages 12 – 27
Sectional door
with curved track One-piece door with horizontal track
Installation Step 1
Determine Header Bracket Location
Installation procedures vary according to garage
door types. Follow the instructions which apply to
your door.
If 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 personal injury
or death could result. Call for professional
garage door service.
WARNING

Header Wall Vertical
Centerline
Vertical
Centerline of
Garage Door
2x4
Unfinished
Ceiling
Structural
Supports
2x4
OPTIONAL CEILING MOUNT
FOR HEADER BRACKET
• Close the door and mark the
inside vertical centerline of
your garage door. Extend the
line onto the header wall
above door.
If headroom clearance is
minimal, you can install the
header bracket on the ceiling.
See page 14.
• If you need to install the
header bracket on a 2x4 (on
wall or ceiling), use lag screws
(not supplied) to securely
fasten the 2x4 to structural
supports as shown.
Example
Distance from top of door
(at highest point of travel) to floor...........................92"
Actual height of door.............................................-88"
Remainder................................................................4"
Add.........................................................................+8"
Bracket height on header wall..............................=12"
(Measure UP from top of CLOSED door.)
Proceed to Step 2, page 14.
13
Header Wall
Highest Point
of Travel
Door
Distance
Jamb
Hardware
Door
Highest Point
of Travel
Header
Wall
Pivot
Distance
ONE-PIECE Door Without Track
• Open your door to the highest point of travel as
shown. Measure the distance from the top of the
door to the floor. Subtract the actual height of the
door. Add 8" to the remainder. (See Example.)
• Close the door and draw an intersecting horizontal
line on the header wall at the determined height.
If the total number of inches exceeds the height
available in your garage, use the maximum
height possible, or refer to page 14 for ceiling
installation.
One-piece door without track
pivot hardware
One-piece door without track
jamb hardware
Read the Safety Instructions on page 12. They also apply to doors without tracks.

Lag Screws
5/16"x9x1-5/8"
Highest
Point of Travel
(of Garage Door)
Vertical
Center
Line
Header
Wall
Garage
Door
Mounting New Header Bracket
10/16/91 - 10/26/91 - 4/5/92
UP
CEILING MOUNT ONLY
Wall
Mounting Holes
Optional 
Wall Mounting
Holes
UP
CEILING MOUNT ONLY
Ceiling Mounting Holes
The nail hole is for positioning
only. You must use lag screws to
mount the header bracket.
The nail hole is for positioning only.
You must use lag screws to mount
the header bracket.
UP
CEILING MOUNT ONLY
Door
Spring
Header
Bracket
2x4
Structural
Support
Vertical
Center
Line
UP
Lag Screws
5/16"x9x1-5/8"
Garage
Door
Vertical
Center Line
Header
Wall
Finished
Ceiling
Header
Bracket
6" Maximum
Vertical
Center Line
Door
Spring
14
You can attach the header bracket either to the
wall above the garage door, or to the ceiling.
Follow the instructions which will work best for
your particular requirements.
Fasten the Header Bracket to the Wall
• Center the bracket on the vertical guideline with
the bottom edge of the bracket on the horizontal
line as shown (with the arrow pointing toward the
ceiling).
• Mark either set of bracket holes (do not use the
holes designated for ceiling mount). Drill 3/16" pilot
holes and fasten the bracket securely to a structural
support with the hardware provided.
Fasten the Header Bracket to the Ceiling
Installation Step 2
Install the Header Bracket
Lag Screw
5/16"-9x1-5/8"
Hardware Shown Actual Size
Lag Screws
5/16"x9x1-5/8"
Highest
Point of Travel
(of Garage Door)
Vertical
Center
Line
Header
Wall
Garage
Door
Mounting New Header Bracket
10/16/91 - 10/26/91 - 4/5/92
UP
CEILING MOUNT ONLY
Wall
Mounting Holes
Optional 
Wall Mounting
Holes
UP
CEILING MOUNT ONLY
Ceiling Mounting Holes
The nail hole is for positioning
only. You must use lag screws to
mount the header bracket.
The nail hole is for positioning only.
You must use lag screws to mount
the header bracket.
UP
CEILING MOUNT ONLY
Door
Spring
Header
Bracket
2x4
Structural
Support
Vertical
Center
Line
UP
Lag Screws
5/16"x9x1-5/8"
Garage
Door
Vertical
Center Line
Header
Wall
Finished
Ceiling
Header
Bracket
6" Maximum
Vertical
Center Line
Door
Spring
• Extend the vertical guideline onto the ceiling as
shown.
• Center the bracket on the vertical mark, no more
than 6" from the wall. Make sure the arrow is
pointing toward the wall. The bracket can be
mounted flush against the ceiling when clearance
is minimal.
• Mark holes designated for ceiling mount only. Drill
3/16" pilot holes and fasten bracket securely to a
structural support with the hardware provided.

Header
Bracket
Belt Pulley
Bracket
Temporary
Support
Header Wall
Garage
Door
The Chamberlain Group, Inc.
Liftmaster Synchro Drive
Attach Tee Rail to Header Brac
k
5/16/92
T-rail
Clevis Pin
5/16"x2-3/4 "
Ring Fastener
Header Bracket
Belt Pulley
Bracket
T-rail
INCREASE
DOWN
TRAVEL
INCREASE
UP
TRAVEL
• Position the opener on the garage floor below the
header bracket. Use packing material as a
protective base.
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 T-rail to clear
the spring.
• Position the belt pulley bracket against the header
bracket.
• Align the bracket holes and join with a clevis pin
as shown.
• Insert a ring fastener to secure.
15
Installation Step 3
Attach the T-rail to the Header Bracket
Clevis Pin
5/16"x2-3/4" Ring Fastener
Hardware Shown Actual Size

Installation Step 4
Position the Opener
Follow instructions which apply to your door type
as illustrated. To prevent damage to steel, aluminum,
fiberglass or glass panel doors, do not rest the
opener on the door without using a 2x4.
SECTIONAL Door & ONE-PIECE Door with Track
A 2x4 laid flat is convenient for setting an ideal
door-to-T-rail distance.
• Raise the opener onto a stepladder.
You will need help at this point if the ladder is
not tall enough.
• Open the door all the way and place a 2x4 laid flat
on the top section beneath the T-rail.
If the top panel hits the trolley when you raise
the door, pull down on the trolley release arm to
disconnect the inner and outer sections. The
trolley can remain disconnected until Step 12 is
completed.
T-rail 2x4
Door
Stepladder
ONE-PIECE Door without Track
• With the door fully open and parallel to the floor,
measure the distance from the floor to the top of
the door.
• Using a stepladder as a support, raise the opener
to the same distance as the door from the floor (it
will be at a slight angle as shown).
• The top of the door should be level with the top of
the opener. Do not position the opener more than
2" above this point.
Top of Opener
Header
Bracket
Top of Door
Stepladder
16
CAUTION
Trolley
Trolley
Release Arm

Installation Step 5
Hang the Opener
Two representative installations are shown.
Yours may be different. Hanging brackets should
be angled, Figure 1, to provide rigid support. On
finished ceilings, Figure 2, attach a sturdy metal
bracket to structural supports before installing the
opener. The bracket and fastening hardware are not
supplied.
• Measure the distance from each side of the opener
to the structural support.
• Cut both pieces of the hanging bracket to required
lengths.
• Drill 3/16" pilot holes in the structural supports.
• Attach one end of each bracket to a support with
5/16"x1-7/8" lag screws.
• Fasten the opener to the hanging brackets with
5/16"-18x7/8" hex screws, lock washers and nuts.
• Check to make sure the T-rail is centered over the
door (or in line with the header bracket if the
bracket is not centered above the door).
• Remove the 2x4. Operate the door manually. If the
door hits the rail, raise the header bracket.
Measure
Distance
Lag Screws
5/16"x1-7/8"
5/16"-18x7/8"
Hex Screws
5/16" Lock Washers
5/16"-18 Nuts
Structural
Supports
Bracket
(Not Supplied)
Lag Screws
5/16"x1-7/8"
(Not Supplied)
5/16"-18x7/8" Screw
5/16" Lock Washer
5/16"-18 Nut
— FINISHED CEILING —
Hidden 
Support
5/16"-18x7/8" Screw
5/16" Lock Washer
5/16"-18 Nut
17
The opener could fall and injure someone if it
is not properly secured. Fasten the opener
securely to structural supports of the garage.
Figure 1
Figure 2
Lag Screw
5/16"-18x1-7/8"
Hex Screw
5/16"-18x7/8" Nut 5/16"-18 Lock Washer 5/16"
Hardware Shown Actual Size
WARNING
RAIL GREASE
NO. 83A4

Grease the top and
underside of the rail
surface where the
trolley slides with rail
grease.

Opener
Terminal Screws
Antenna
Right Panel
of Opener
Multi-Function
Door Control Panel
Multi-Function
Door Control Panel
Terminal Screws
RED
WHITE
The Chamberlain Group, Inc.
Liftmaster Belt Drive CDO
Install Wall Control
3/5/92 - 3/13/92
LIGHT
LOCK
Door Control
Button
Light Button
Lock Button
KG KG
1
3
9
75
1
3
9
75
23
1
12
Installation Step 6
Install the Multi-Function
Door Control Panel
18
Children operating or playing with a garage
door opener can injure themselves or others.
The garage door could close and cause
serious injury or death. Install the door control
(or any additional push buttons) out of the
reach of children and away from all moving
parts of the door and door hardware, but
where the garage door is visible. Do not allow
children to operate the push button(s) or the
remote control transmitter(s).
A moving garage door could injure someone
under it. Activate the opener only when the
door is properly adjusted, you can see it clearly,
and there are no obstructions to door travel.
• Strip 1/4" of insulation from one end of the bell
wire; connect the wire to the two screw terminals
on the back of the door control by color: white to 2
and white/red to 1.
• Locate the door control within sight of the door
at a minimum height of 5 feet where small
children cannot reach, and away from all
moving parts of the door and door hardware.
Fasten the Multi-Function Door Control securely
with 6ABx1" screws. If installing into drywall, drill
5/32" holes and use the anchors provided.
• Run the bell wire up the wall and across the ceiling
to the opener. Use insulated staples to secure the
wire in several places. Be careful not to pierce the
wire with a staple, thereby resulting in a short.
• Receiver terminal screws and the antenna are
located on the right panel of the opener. Position
the antenna wire as shown.
• Then connect the bell wire to the opener terminal
screws: white to 2 and white/red to 1.
• Remember to affix the User Safety Instruction
label to the wall near the door control, and the
Maintenance Instruction label in a prominent
location on the inside of the garage door.
If the label adhesive will not adhere to your garage
wall surface (or becomes lose with time) use tacks
to secure the label alongside the door control.
Page 32 explains how to operate the opener using
the lighted push button and the Lock & Light
features available on the Multi-Function Door
Control Panel.
Dry Wall Anchors Insulated 
Staples
6AB x 1" Screw
Multi-Function Door Control
Hardware Shown Actual Size
Outside Keylock Accessory Connections
To opener terminal screws: white to 2; white/red to 1
WARNING
CAUTION
WARNING
Do NOT connect the power and operate the
opener at this time. The trolley will travel to the
full open position but will not return to the
close position until the sensor beam is
connected and properly aligned.
See Safety Reversing Sensor Instructions
beginning on page 21.

• Install a 75 watt maximum light bulb in each
socket. The lights will turn ON and remain lit for
approximately 4-1/2 minutes when power is
connected. Then the lights will turn OFF.
• If the bulbs burn out prematurely due to vibration,
replace them with "Garage Door Opener" bulbs.
• Slide lenses into guides as shown. Snap bottom
tabs into lens slots.
• For convenience, the lenses may be installed
after Adjustment Step 4 on page 30.
• Reverse the procedure to remove the lenses.
Installation Step 7
Install the Lights and the Lenses
Installation Step 8
Attach the Manual Release
Rope and Handle
Do not use the red handle to pull the door
open or closed. The rope knot could become
untied and you could fall. Use the manual
release only to disengage the trolley and, if
possible, only when the door is closed.
Garage doors are heavy. If the door is open
when the handle is pulled, the door could
close inadvertently if it is not properly
balanced. Serious injury may result to persons
under the door. Make sure the doorway is clear
of persons and obstructions before pulling
handle when door is open.
• Thread one end of the rope through the hole in the
top of the red handle so "NOTICE" reads right side
up as shown. Secure with an overhand knot.
The knot should be at least 1" from the end of the
rope to prevent slipping.
• Thread the other end of the rope through the hole in
the release arm of the outer trolley.
• Adjust rope length so the handle is 6 feet above the
floor. Secure with an overhand knot .
If it is necessary to cut the rope, heat seal the cut
end with a match or lighter to prevent unraveling.
Trolley
NOTICE
Overhand
Knot
Manual
Release Handle
Rope
Overhand
Knot
Trolley
Release Arm
19
75 Watt Max.
Light Bulb
Lens
Guide
Lens Tab
Lens Slot
Lens Tab
75 Watt Max.
Light Bulb
WARNING

To prevent electrocution, remove power from
the garage door opener and from the circuit
you plan to use for the permanent connection.
To reduce the risk of electric shock, your garage
door opener has a grounding type plug with a third
grounding pin. This plug will only fit into a grounding
type outlet.
If the plug doesn't fit into the outlet you have,
contact a qualified electrician to install the proper
type outlet.
Right Wrong
Installation Step 9
Electrical Requirements
Ground Tab
Green Ground
Screw
Ground Wire
Black
Wire
Permanent Wiring
Connection
White Wire
Black
Wire
• To make a permanent connection through the
7/8" diameter hole in the top of the opener
(according to local code):
• Remove the opener cover screws and set the
cover aside.
• Remove the attached 3-prong cord.
• Connect the black (line) wire to the screw on the
brass terminal; the white (neutral) wire to the
screw on the silver terminal; and the ground wire
to the green ground screw. The opener must be
grounded.
• Reinstall the cover.
20
To prevent electrocution or fire, installation
and wiring must be in compliance with local
electrical and building codes.
Do NOT use an extension cord, 2-wire adapter,
or change the plug in anyway to make it fit
your outlet.
Right Wrong
To avoid installation difficulties,
do not run the opener at this time.
To avoid installation difficulties,
do not run the opener at this time.
If permanent wiring is required by your local code, refer to the following procedure:
WARNING
WARNING