Replacing a garage door opener chain drive module

Posted by sere on February 11th, 2020

I have twoopener noreferrer" target="_blank"> garage doors with chain garage door opener.

This part of each door is broken once.

The main spring of the first door breaks and the weight of the door causes the sprocket to brake.

The sprocket of the second door just brake.

My garage door opener is Chamberlain Liftmaster Professional 1/2 HP, but I think there are other brands of garage door opener with the same design.

If your door opener makes a noise, but the door remains closed, if the chain is relaxed and suspended, you will know if your chain drive sprocket has broken, if you find the broken sprocket on the top of the opener or on the floor.

Three serious injuries or deaths are mentioned in the instructions attached to the replacement part.

If you are not satisfied with your ability, you should have a professional garage door technician to repair your garage door opener.

On the other hand, if you have confidence in your abilities and are willing to take the risk of serious injury or death, then move on anyway.

Before opening the garage door, make sure to isolate electrical energy by tripping the circuit breaker or unplugging the garage door power cord.

Make sure the garage door main spring is in good condition and adjusted properly.

The tools I use are 1/4 nut drive, Philips screwdriver, slotted screwdriver, ratchet with 5/16 sleeve, 1/2 wrench and ladder.

I also wear safety glasses.

I bought a kit from Amazon for . 56.

It includes the chain drive module and some extra parts that I don\'t need to replace, like the drive screw and some bushing.

There are three cross screws on the back cover of the garage door opener.

The first two only need to be released, and the lid slides down when you remove the bottom screw.

You can hang the lid on the wire inserted.

This should give you the space to replace the chain drive module.

There are three screws that fix the chain drive module on the main body of the opener.

They have 5/16 hexagonal heads.

There is a gear at the bottom of the chain drive module, which must be removed before removing the old module and installing the new module.

The pinion is supported by a plastic pin passing through the shaft.

This plastic pin has two labels and you have to pull gently to the side in order for the pin to slip out.

Once this pin comes out, the gear slides down from the shaft.

After removing the pinion from the bottom of the shaft, a new module can be installed.

To make it easier to reinstall the pinion and its fixed PIN, position the hole of the pin on the shaft so you can see it.

By placing the pinion on the shaft and inserting it into the fixing clip, reinstall the pinion on the shaft.

Reinstall the three screws that hold the module on the main body of the opener.

Slide the lid back to the top two screws, then tighten the bottom screws, then tighten the top two screws.

In order to have some slack on the chain, in order to be able to put it back on the sprocket, you need to loosen the nut at the end of the chain at the end of the bolt, which is attached to the trolley.

Put the chain on the new Sprocket.

Some garage door openers are different, but I make sure my openers are in the lower position of the door and the trolley is connected to the door in the lower position.

Tighten the nut at the end of the bolt and at the end of the chain.

Tighten the jam nut once your chain has proper tension.

Restore power to the garage door opener.

Test it and make any necessary adjustments to the opener.