Model 8155W - Chamberlain 8160W Manual

Assembly
1 Attach the Rail to the Garage Door Opener

MODEL 8155W

To avoid possible SERIOUS INJURY to finger from moving garage door opener:
• ALWAYS keep hand clear of sprocket while operating opener.
• Securely attach sprocket cover BEFORE operating.
To avoid SERIOUS damage to garage door opener, use ONLY those bolts/fasteners mounted in
the top of the opener.
NOTE: ONLY use the bolts removed from the garage door opener. Place the garage door opener on
the packing material to prevent scratching.
1. Remove the two bolts from the top of the garage door opener.
2. Align the rail and the styrofoam over the sprocket. Cut the tape from the rail, belt, and
styrofoam.
3. Fasten the rail with the previously removed bolts.
4. Position the belt around the garage door opener sprocket.
5. Attach the sprocket cover over the garage door opener sprocket and attach with hex screws.
Washered Bolts
5/16"-18 x 1/2"
(Mounted in
door opener)
Hex Screws 8 x 3/8"
Sprocket
Cover
the garage
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)
9
(To motor unit)
Nut Ring
AFTER RELEASE
1-1/4"
(3.18 cm)