Install Belt; Set The Belt Tension - Craftsman 139.53800SRT Owner's Manual

Assembly Step 4
Install the Belt & Set the Belt Tension
1. Drop the notched side of the trolley clip into the
retaining slot on top of the trolley (see Figure 1).
2. Grasp the clip connector at the end of the belt and
slip it through the belt pulley bracket from behind,
around the pulley and toward the trolley.
3. Fasten the belt clip connector to the trolley clip
with a master link:
• Push pins of master link bar through holes in
trolley clip and belt clip connector.
• Push master link cap over pins and onto pin
notches.
• Slide clip-on spring over cap and onto pin
notches until both pins are securely locked in
place.
4. With the trolley against the screwdriver, dispense
the belt along the rail and around the opener
sprocket. The sprocket teeth must engage the
belt (Figure 2).
5. Use the second master link to connect the belt to
the flat end of the trolley threaded shaft (Figure 1).
Check to make sure the belt is not twisted.
6. Remove the screwdriver.
Figure 1
Belt Clip Connector
7. Insert the trolley threaded shaft through the hole
in the trolley.
8. Hold the belt at the trolley shaft to avoid twisting
as you thread the spring/trolley nut by hand on
the shaft until finger tight against the trolley
(Figure 3).
9. Insert a screwdriver tip into one of the slots of the
nut ring, and hold firmly as you release the spring
by turning the nut clockwise with a 7/16" open end
wrench. Turn until the spring snaps open.
When installation is complete, you may notice some
belt droop with the door closed. This is normal. If the
belt returns to the position shown when the door is
open, do not re-adjust the belt.
Master Link
Clip-On Spring
Master
Link Cap
Slip Belt Clip Connector
through Pulley Bracket
from this direction
and attach to trolley clip
Belt
Pulley
10
Serious injury can result if fingers become
entangled in moving opener sprocket. Attach
belt cap retainer securely. Never operate
opener while your hand is near the opener
sprocket.
Figure 2
Master Link
Clip-On Spring
Master
Link Cap
Trolley
Clip
Pin Notch
Belt
Clip Connector
Trolley
Hole
Figure 3
WARNING
Opener
Sprocket
Pin Notch
Master
Trolley
Link Bar
Threaded Shaft
Master
Link Bar
Trolley Threaded Shaft
Spring/ Trolley Nut
Nut
Ring