Step 5: Arm And Turnbuckle Shaft Adjustments - Chamberlain LiftMaster BG770 Installation And Maintenance Manual

Arm and Turnbuckle Shaft Adjustments
Step 5:
CAUTION
Turn off power before making any adjustments.
MODEL BG770 ADJUSTMENTS
1 If necessary, rotate the pulley on the motor by hand until the crank arm on the gear
reducer is perfectly aligned with the turnbuckle shaft (see Figure 11). This is the lowest
point of the arm travel and should be preset in this position at the factory.
2 If the arm is not level, loosen the jam nuts at both ends of the turnbuckle shaft Insert a
screwdriver or other similar tool into the hole in the shaft. Rotate the shaft either CW or
CCW as necessary until the gate arm is in the desired horizontal position. Retighten jam
nuts.
BG770 TURNBUCKLE SHAFT ALIGNMENT
If necessary align turnbuckle shaft with center of crank arm for lowest point of travel of pivot arm
(see Figure 12).
Pivot Arm
Pulley
Crank Arm
Figure 11: Model BG770
01-G0674F13
01-G0674F14
Figure 12
Installation
Jam Nut
Turnbuckle Shaft
Doc 01-G0674
16
Rev E