Chamberlain 7220 1/2HP Guida Utente

9

• Attach the trolley threaded shaft to the trolley with

the lock washer and nuts as shown.

• As a temporary stop, insert a screwdriver into the

hole in the front end of the T-rail.

• Slide the trolley assembly along the rail to the

screwdriver stop. 

NOTE: If trolley hits against any nuts on the T-rail,
the bolts and nuts were attached from the wrong
side and must be repositioned. Review Assembly
Step 1.

Temporary Stop
Screwdriver

Trolley
Threaded
Shaft

Inner Nut
5/16"

Lock
Washer
5/16"

Outer Nut
5/16"

Trolley

• Place the opener on packing material to protect

the cover. For convenience, put a support under
the cable pulley bracket.

• Remove the two 5/16"-18x1/2" washered screws

mounted in the top of the motor unit.

• Align the holes in the back section of the T-rail with

the holes in the motor unit.

• Fasten the rail with the two washered screws

previously removed. Tighten securely. Remember
to use only these screws! Any other screws
will cause serious damage to the opener.

• Insert a 5/16"-18x7/8" hex screw into the cover

protection bolt hole in the T-rail as shown. Tighten
securely with a 5/16" lock washer and nut.

NOTE:  This screw prevents trolley over-travel. Keep
a 2" minimum between the trolley and this screw
when adjusting travel limits (see page 28).

Washered Screw
5/16"-18x1/2"

T-Rail
(Back Section)

Cover
Protection
Bolt Hole

Nut
5/16"-18

Hex Screw
5/16"-18x7/8"

Lock Washer
5/16"-18

Nut
5/16"-18

Lock Washer
5/16"

Hex Screw
5/16"-18x7/8"

To avoid serious damage to opener, ONLY use screws
mounted in top of motor unit.

Lock Washer
5/16"

Nut
5/16" -18