Although a chain drive garage door opener can be a little noisy in operation and some feel it’s more demanding of maintenance than belt or screw drive openers, there is really not that much that can go wrong. If you lubricate the chain every now and again, this type of opener will serve you well for many years.
If the Chain Starts to Jump
At some point though, the sprocket which engages with the chain to raise and lower the door may need replacing. If the chain on your door opener begins to skip or jump when the door is being raised, it’s a sign that the teeth on the sprocket have worn. Fortunately, replacing the sprocket, which is located at the top of the motor, is an easy enough DIY task. Here is a simple, step-by–step guide to explain the process.
10 Steps to Changing the Chain Drive Sprocket
1) Pull down on the manual release cord which disengages the drive trolley from the chain arm. Now you can lower the door manually.
2) After lowering the door, use a stepladder to climb up and disconnectthe power supply to your garage door opener. Do this by unplugging the power cable from the ceiling outlet.
3) You will find a snap on cover where the chain engages with the sprocket atop the motor. Use a screwdriver to remove the cover.
4) Now relocate your stepladder to the end of the chain arm nearest to the garage door. You will see a chain pulley on the top of the chain arm. Loosen the bolts on the pulley and slide it just an inch towards the motor.
5) Move your stepladder back to the motor of your garage door opener. Using a ratchet and socket, undo the machine bolts which hold the sprocket in place and remove them. Save the bolts.
6) Use your screwdriver to pry up the sprocket and then remove it from the motor. Take the chain from the sprocket and lay it over the chain arm.
7) Now use your socket and ratchet and the bolts you saved to install the new sprocket. Fit the chain around the sprocket.
8) Return your stepladder to the end of the chain arm. Climb up and slide the pulley towards the end of the chain arm until the chain is tight, then slide it back toward the motor just enough so the chain touches the top of the chain arm. Now you can tighten the bolts that hold the pulley in place.
9) Now reposition your stepladder to access the motor one last time. Fasten the sprocket cover back in place and plug in the power to the garage door opener.
10) Return to the floor and pull the manual release cord to refit the trolley to the chain arm, putting your door opener back into automatic mode.
Now you should find you can raise your door using the opener without the chain jumping. If replacing the sprocket doesn’t cure the problem or you simply prefer not to tackle this task yourself, you can always call on your local garage door installation and repair service to resolve the problem instead.