7
Screwdriver
Nut Ring
Spanner
Spring Nut
Header Sleeve
Nut Ring
Trolley
Nut Ring
Trolley
25mm
32mm
BEFORE
AFTER RELEASE
ASSEMBLY STEP 7
Set Belt Tension
• Thread spring nut onto the carriage bolt until finger
tight. Insert a screwdriver tip into one of the slots of the
nut ring and brace it firmly against the header sleeve.
• Place a spanner on the square end of the spring nut,
slightly rotate nut about 1/4 turn clockwise until nut ring
is released against header sleeve.
This sets spring for optimum belt tension. Belt may slip off
pulley if belt is too loose. If belt does slip, re-tighten spring
nut by turning nut clockwise a half turn.
Do NOT over-tighten belt.
Hex Screws
Belt Pulley Cover
Mounting Plate
Opener Belt Pulley
ASSEMBLY STEP 8
Attach the Belt Pulley Cover
• Grease the Belt and Pulley liberally with the grease
provided in the hardware bag.
• Position the belt pulley cover over the opener belt
pulley so the three holes in the cover align with the
three holes in the mounting plate. Attach with hex
screws provided.
Hex Screw
HARDWARE
To avoid possible SERIOUS INJURY to fingers from moving
garage door opener:
• ALWAYS keep hands clear of belt pulley while operating opener.
• Securely attach belt pulley cover BEFORE operating.
Summary of Contents for MT3850EVO
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