How To Repair Garage Door Cables

This post will show you the exact steps needed to change your garage door cables. Please note, this is an advanced repair that involves working with springs, which might be extremely dangerous. We at “Calgary Garage Door Fix” always suggest contacting your local garage door professionals for performing such maintenance, but for those who would like to do it by themselves, we decided to post this garage door cable replacement guide.

These directions based on this type of torsion spring setup. Front-mounted with a center bearing plate and a spring or springs attached in the center. It has cable drums inside the end bearing plates with cables coming up and over the backside of the cable drums.

If your garage door has a different type of spring set up than the one shown, do not use these directions, they might differ for your particular door. Serious injury and even death can happen as a result of improper handling of garage door springs and cables.  We recommend that you call a professional if your spring assembly is different from the one shown here.

Bottom brackets and cables should always be replaced in pairs, to ensure continuity in overall cable length.

As you will see in this post, due to the amount of disassembly required to replace your broken bottom bracket or cable, now is the time to consider replacing the spring or springs.

Replacing these additional components now will save you time in the future.

The following tools required for this repair:

a metal rod or winding bars, two pairs of locking pliers, a ladder, a file, various sockets, and wrenches sized 3/8 7/16 1/2, and 9/16.

First, unplug your garage door opener from the electrical outlet and remove the arm that connects the opener to the door. Next, lock your door in a closed position and place vise-grips or clamps on the track above the middle roller. This will ensure the door does not open while you’re working.

Position the ladder in a manner that will allow you to keep your face away from the winding cone and winding bars as you unwind the spring. Insert one winding bar into the winding cone. While firmly holding onto the winding bar, loosen the set screws in the winding cone. Ensure that the set screws are not in contact with the door shaft. Insert the second winding bar fully into the winding cone, lift on the second winding bar and remove the first bar. Then insert the winding bar into the next hole on the cone and repeat this process until all tension removed from the spring.

You will want to count the total amount of quarter turns you removed from the spring as you are unwinding it. This is the same amount of tension that you will be reapplying later.

Take your time and concentrate on what you are doing, eliminate all distractions from your work area before unwinding or winding torsion springs. Working with springs requires full concentrations as they are the most hazardous component of the entire assembly. If your garage door has two torsion springs, repeat this process on the other spring. All tension must be removed from the garage door before you can proceed.

First, loosen the set screws on the cable drum, then slide the cable drum away from the end bearing plate. Now you can remove the cable.

Unscrew the bolt holding the bottom track bracket to the wall and remove the fasteners that hold the bottom bracket in place.

Slide the track to the side and remove the bottom bracket from the door. Remove the cable from the bracket and then completely remove the cable from the door. Prepare the new cable by cutting any pieces of tape that wrapped around it.

Now attach the new cable to the bottom bracket, install the roller and thread the cables behind the door.

Install the bottom bracket onto the garage door.

Align the bracket with the holes that it was removed from and reinstall the fasteners, making sure to tighten them before proceeding. 

Now you should reinstall and tighten the lag bolt into the track bracket. Take care to reposition the track bracket in the same location it was originally.

Now ensure the cable is clear of any obstructions and is running directly from the bottom bracket to the cable drum.

Insert the cable into the slot in the drum, make sure the cable is correctly seated into the cable drum. Ensure the cable is appropriately tracking in the grooves. Slide the drum firmly against the end bearing plate and tighten the set screws, do not overtighten them.

Holding the drum in a manner that will keep the cable tight on the cable drum,  place locking pliers on the shaft, letting them rest against the wall. This will hold the cable tight on the cable drum.

Insert the winding bar into the winding cone, making sure the winding bar inserted all the way. We will be winding the springs the same amount of quarter-turns that were removed from the spring initially.

Continue to wind the spring until the proper amount of turns have been applied.

Once the correct number of turns has been reached, let the bottom winding bar rest against the door and tighten the set screws against the shaft. Insert the second bar into the winding cone and lift slightly, removing the bottom bar and testing the strength of the set screws.

Tighten the set screws if needed, then repeat this process on the other side of the door with the second torsion spring.

Wind the spring until the proper number of turns are in place, tighten the set screws, remove the bottom winding bar and test the grip of the set screws.

Finally slowly remove the locking pliers from the shaft, making sure the shaft and spring are secure. Remove the first clamp from the track then unlock the door and while placing your foot on the step plate of the door, remove the second clamp from the track.

Now maintaining a firm grip on the door, remove your foot from the step plate and raise the garage door.

Check the balance of the door as you raise it. Does the door open effortlessly and fully or is the door heavy to lift? If adjustments are required, re-clamp and lock the door.

Using the same process, add or reduce the tension on the spring. Never add more than one-half turn of tension at a time.

After you’ve added tension to the springs, don’t forget to tighten the set screws again. Be sure to insert the winding bar and check the grip of the set screws before removing the other bar.

Repeat the process of removing the clamps, unlocking the door, and testing the door for proper balance. Verify that the door is not too heavy and not too light. Now reattach the arm to the garage door opener and plug your opener into the electrical outlet.

Congratulations! You’ve changed your garage door cables! Keep in mind, this is an advanced repair and if done incorrectly, can be extremely dangerous. This post explains the proper steps that should be taken to change the cables on this type of door. If your door is different, this procedure might not be the best one to follow. If in doubt, always contact your local garage door expert.