Assembly Section: Pages; Fasten T-Rail To Opener; Tighten The Belt - Chamberlain Lift-Master Professional 1270 Owner's Manual

ASSEMBLY STEP 1
Attach the T-Rail To the Opener
• Remove the two washered screws mounted in top
of opener.
• Align T-rail and styrofoam over opener sprocket.
• Cut tape from T-rail, belt and styrofoam.
• REMOVE STYROFOAM.
• Insert both washered screws through the T-rail into
the opener. Tighten both screws securely .
USE ONLY THESE SCREWS! Any other screws
will cause serious damage to the opener.
Position belt over the opener sprocket.
ASSEMBLY STEP 2
Set the Belt Tension
• By hand, thread the spring trolley nut on the
threaded shaft until it is finger tight against the
trolley. Do not overtighten.
• Insert a small screwdriver tip into one of the insert
slots of the nut ring, and hold firmly.
• Using an open end wrench at the square end,
slightly rotate the assembly clockwise until the nut
ring is released against the trolley, providing
tension for the best operation of the opener.

Assembly Section: Pages 6 - 7

To fasten rail, use only those screws mounted
in the top of the opener. Any other screws will
cause serious damage to the opener.
Belt
USE ONLY THIS
TYPE AND SIZE
SCREW
Belt
Open End
Wrench
Trolley
6
CAUTION
Washered Screw
5/16"-18x1/2"
Styrofoam
T-Rail
Hole
Washered Screw
5/16"-18x1/2"
Opener
Sprocket
T-Rail
Hole
T-Rail
Hole
Trolley
Trolley
Threaded
Shaft
Spring
Trolley Nut
Trolley
Nut
Threaded Shaft
Ring
Nut Ring
Insert Slot
Screw
Square End
Driver