Tighten The Chain; Installation - Craftsman 139.53910D Owner's Manual

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.
Figure 1 Trolley
Outer Lock Threaded
Nut Washer Shaft
Figure 2
Chain
I
Base of Rail Mid'length of Rail
INSTALLATION
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of SEVERE INJURY or DEATH:
1. READAND FOLLOWALL 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
SEVEREINJURYor 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 releasehandle 6 feet (1.83 m) above
floor.
7. NEVERconnect garage door opener to power source
until instructed to do so.
8. NEVERwear 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. Placeentrapment warning label on wall next to garage
door control.
11. Placemanual release/safety reversetest 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.
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