Chamberlain LiftMaster PREMIUM Serie Mode D'emploi page 5

Assembly
2 Tighten the Belt
1. By hand, thread the spring trolley nut on the threaded shaft until it is finger tight against the
trolley. Do not use any tools.
2. Insert a flathead screwdriver tip into one of the nut ring slots and brace it firmly against the
trolley.
3. Tighten the spring trolley nut with an adjustable wrench or a 7/16" open end wrench about a
quarter turn until the spring releases and snaps the nut ring against the trolley. This sets the
spring to optimum belt tension.
1
Spring Trolley Nut
2
Nut ring
slot
3
Nut Ring
BEFORE
1"
(2.5 cm)
4
(To motor unit)
Nut Ring
AFTER RELEASE
1-1/4"
(3.18 cm)