Craftsman 139.53975SRT1 Owner's Manual page 10

ASSEMBLY STEP 4
Install the Chain/Cable
and Attach the Sprocket Cover
1. Pull the cable around the idler pulley and toward
the trolley.
2. Connect the cable loop to the retaining slot on the
trolley, as shown:
• From below, push pins of master link bar up
through cable loop and trolley slot.
• 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.
3. With the trolley against the pliers, dispense the
remainder of the cable/chain along the rail toward
the motor unit and around the sprocket. The
sprocket teeth must engage the chain.
4. Check to make sure the chain is not twisted, then
connect it to the threaded shaft with the
remaining master link.
5. Thread the inner nut and lock washer onto the the
trolley shaft.
6. Insert the trolley threaded shaft through the hole
in the trolley. Be sure the chain is not twisted.
7. Loosely thread the outer nut onto the trolley shaft.
8. Remove the locking pliers.
9. Align the tabs on the sprocket cover with the slots
in the mounting plate. Squeeze cover and insert
tabs in slots.
Master Link
Clip-On Spring
Cable
Loop
Idler
Pulley
Cable
10
WARNING
To avoid possible SERIOUS INJURY to fingers from
moving garage door opener:
CAUTION
• ALWAYS keep hand clear of sprocket while operating
opener.
• Securely attach sprocket cover BEFORE operating.
Dispensing Carton
Keep Chain and Cable
Taut When Dispensing
Master Link
Clip-On Spring
Master
Link Cap
Trolley
Threaded
Shaft
Round
Hole
Slotted
Hole
Sprocket
Cover
Master
Link Bar
Front
Tab Slot
Leave Chain and Cable
Inside Dispensing
Carton to Prevent Kinking.
Master
Link Cap
Pin
Notch
Master
Link Bar
Motor Unit
Sprocket
Back
Tab Slot
Mounting
Plate