Chamberlain WhisperDrive SECURITY+ 459950 Manuel Du Propriétaire page 10

ASSEMBLY STEP 4
Install the Belt
1. Pull the belt around the idler pulley and toward the
trolley. The ribbed side must contact the pulley.
2. Hook the trolley connector into the retaining slot on the
trolley as shown (Figure 1).
3. With the trolley against the screwdriver, dispense the
remainder of the belt along the rail length toward the
motor unit and around the sprocket (Figure 2). The
sprocket teeth must engage the belt.
4. Thread the inner nut and lock washer onto the trolley
threaded shaft (Figure 3). Check to make sure the belt
is not twisted.
5. Insert the trolley threaded shaft through the hole in the
trolley (Figure 3). Be sure the belt is not twisted.
6. Loosely thread the outer nut onto the trolley threaded
shaft.
7. Remove the screwdriver.
Figure 1
Trolley
Connector
Retaining Slot
To avoid possible SERIOUS INJURY to fi ngers from
moving garage door opener:
• ALWAYS keep hand clear of belt pulley while
operating opener.
• Securely attach belt pulley cover BEFORE operating.
Figure 2
Figure 3
Trolley
Threaded Shaft
Hole
Outer Nut
10
Sprocket
Inner Nut
Lock Washer