Chamberlain 8355 - Tighten the Belt

5
2 Tighten the Belt
2.1 By hand,thread the spring trolley nut on the threaded shaft until it is finger tight against
the trolley.Do notuse any tools.
Spring Trolley Nut
(To motor unit)
2.2 Insert a flathead screwdriver tip into one of the nut ring slots and brace it firmly against the trolley.
Nut ring
slot
2.3 Tighten the spring trolleynut with an adjustable wrench or a 7/16" open end wrench about a quarter turn until the spring releases and snaps the nutring againstthe trolley.This setsthe spring to
optimum belttension.
Nut Ring
Nut Ring
AFTER RELEASE
1-1/4"
(3.18 cm)
BEFORE
1"
(2.5 cm)