Craftsman 139.18451D Garage Door Opener User Manual


 
11
INSTALLATION
ASSEMBLY STEP 5
Tighten the Chain
Spin the inner nut and lock washer down the trolley
threaded shaft, away from the trolley.
To tighten the chain, turn outer nut in the direction
shown (Figure 1).
When the chain is approximately 1/4" (6 mm) above
the base of the rail at its midpoint, re-tighten the inner
nut to secure the adjustment.
Sprocket noise can result if chain is too loose.
When installation is complete, you may notice some
chain droop with the door closed. This is normal. If the
chain returns to the position shown in Figure 2 when the
door is open, do not re-adjust the chain.
NOTE: During future maintenance, ALWAYS pull the
emergency release handle to disconnect trolley before
adjusting chain.
NOTE: You may notice loosening of chain after
Adjustment Step 3 (Test the Safety Reversal System).
Check for proper tension and readjust chain if necessary.
Then repeat Adjustment Step 3.
You have now finished assembling your garage door
opener. Please read the following warnings before
proceeding to the installation section.
Outer
Nut
Lock
Washer
Trolley
Threaded
Shaft
Inner Nut
To Tighten
Inner Nut
To Tighten Outer Nut
Base of Rail
Mid length of Rail
Chain
1/4" (6 mm)
Figure 1
Figure 2
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of SEVERE INJURY or DEATH:
WARNING
WARNING
WARNING
1. READ AND FOLLOW ALL INSTALLATION WARNINGS
AND INSTRUCTIONS.
2. Install garage door opener only on properly balanced
and lubricated garage door. An improperly balanced
door may not reverse when required and could result in
SEVERE INJURY or DEATH.
3. ALL repairs to cables, spring assemblies and other
hardware MUST be made by a trained door systems
technician BEFORE installing opener.
4. Disable ALL locks and remove ALL ropes connected to
garage door BEFORE installing opener to avoid
entanglement.
5. Install garage door opener 7 feet (2.13 m) or more
above floor.
6. Mount emergency release handle 6 feet (1.83 m) above
floor.
7. NEVER connect garage door opener to power source
until instructed to do so.
8. NEVER wear watches, rings or loose clothing while
installing or servicing opener. They could be caught in
garage door or opener mechanisms.
9. Install wall-mounted garage door control:
within sight of the garage door.
out of reach of children at minimum height of 5 feet
(1.5 m).
away from ALL moving parts of the door.
10. Place entrapment warning label on wall next to garage
door control.
11. Place manual release/safety reverse test label in plain
view on inside of garage door.
12. Upon completion of installation, test safety reversal
system. Door MUST reverse on contact with a
1-1/2" (3.8 cm) high object (or a 2x4 laid flat) on
the floor.