Chamberlain 459950 Manual De Usuario

10

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.

3.   With the trolley against the screwdriver, dispense the 

remainder of the belt along the rail length toward the 
motor unit and around the belt pulley. The belt pulley 
teeth must engage the belt.

4.   Check to make sure the belt is not twisted. Connect 

the trolley threaded shaft with the master link, as 
illustrated:

 

•   Push pins of master link bar through holes in end of 

belt and trolley threaded shaft.

 

•  Push master link cap over pins and past pin notches.

 

•   Slide clip-on spring over cap and onto pin notches 

until both pins are securely locked in place.

5.   Insert the trolley threaded shaft through the hole in the 

trolley. Be sure the belt is not twisted. 

6.   Hold the belt at the trolley shaft as you thread the 

spring nut by hand onto the shaft until fi nger tight 
against the trolley. DO NOT use any tools.

7.  Remove the screwdriver.

8.   Position the belt cap retainer over the motor unit belt 

pulley as shown and fasten to the mounting plate with 
8x3/8" hex screws provided.

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.

Spring/Trolley Nut

Hex Screw 8x3/8"

Motor Unit
Belt Pulley

Belt Cap
Retainer

Mounting
Plate

Master Link
Clip-On Spring

Master 
Link Cap

Master 
Link Bar

Pin
Notch

Retaining
Slot

Trolley 
Hole

Trolley
Threaded
Shaft

8x3/8" Hex Screws

Spring Nut

Idler Pulley

Trolley 
 Connector