Chamberlain B4603TC - STEP 5 Tighten the Belt; STEP 6 Install the Sprocket Cover

STEP 5 Tighten the Belt
1. By hand, thread the spring trolley nut on the threaded shaft until it is nger tight against the trolley.
Do not use any tools. Remove the screwdriver.
2. Insert a athead screwdriver tip into one of the nut ring slots and brace it rmly 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.
BEFORE
1” (2.5 cm)
Nut Ring
Spring
Trolley Nut
Nut Ring Slot
Nut Ring
AFTER
1-1/4” (3.18 cm)
11
To avoid possible SERIOUS INJURY to nger from moving garage door opener:
l ALWAYS keep hand clear of sprocket while operating opener.
l Securely attach sprocket cover BEFORE operating.
1. Position the sprocket cover over the sprocket as shown and fasten to the mounting plate with #8x3/8"
hexscrews provided.
Youhavenownishedassemblingyourgaragedooropener.Pleasereadthefollowingwarningsbefore
proceeding to the installation section.
Hex Screw #8x3/8”
(Packed with the sprocket cover)
HARDWARE
Sprocket Cover
Hex Screw
Assembly
STEP 6 Install the Sprocket Cover