How Do You Fix Jerky on a Treadmill?

How Do You Fix Jerky on a Treadmill

Despite all movements on the treadmill belt during use, the machine itself should not jerk.

Jerking usually means there is a lot of space, and the running belt is slipping.

Misalignment of the running belt or motor drive belt slip is also a common cause of treadmill jerking.

It is essential to fix a treadmill jerking problem to avoid falling on a treadmill, leading to injury or damage to the treadmill.

With a quick and straightforward method, it is possible to solve the treadmill jerking problem.

The following guide will help you stop your treadmill from jerking.

Fix The Slipping Treadmill Belt

When you stop the treadmill and lift the belt off the deck with your hand, the free space should be approximately 7 to 10 cm.

Jerking may mean the room is excess and the belt is slipping.

Tighten the belt using the Allen key that comes with the treadmill at the time of purchase.

However, if you lost the Allen key or your treadmill is a second-hand one, you can purchase a similar one at your local hardware store.

Insert the Allen key into the screw on the right side of the belt and turn it a quarter-turn clockwise.

Use the same method to loosen it if it is too tight. You may need to centre the belt as well if there is misalignment. To do this, use the same Allen key to turn the roller screw clockwise until the belt is centred. Allow it to move on its own a few times and see whether it is turning without moving sideways.

Slippery floors can cause the machine to move slightly. To prevent this, place the device on a mat, and it should remain stable in one place.

Keep in mind that some treadmills come with loose belts than others, depending on the brand.

That means you can find the belt a little loose in some brands even before using the treadmill for the first time. Walk on the treadmill for a few minutes to see if it is still jerking. If the jerking is still present, you will need to tighten the mounting screws to eliminate slip.

If the above method does not solve the running belt problem or is still jerking violently, it is advisable to stop the training and unplug it from the power outlet.

At this point, you may need to call a professional to help fix the problem.

You will probably find the manufacturer contact online or in the user manual. When explaining the steps to correct the problem, the technician can run diagnostics to see if they can find the problem.

Also read: What Maintenance is Required For a Treadmill?

Adjust The Motor Drive Belt

The motor drive belt is also a common cause of treadmill jerking.

If that is the case, follow the below steps to protect it from sliding during the movement.

Turn off the treadmill and remove the motor cover by removing the screws that secure it in place.

Sometimes it is necessary to turn the treadmill over to remove the cover.

Once you remove the cover, check for the black rubber parts that indicate that the drive belt is worn or slippery.

If the motor belt damage is extensive, you may need to buy a new one.

Proceed and loosen the screws that secure the motor in place.

Once it is loose, tighten the drive belt. Tighten the treadmill motor until it is secure in its place.

Check the drive belt carefully as you slowly start the treadmill with no one running on it at a 1 or 2 mph speed and gradually increase to about six mph.

If there is no more jerking, stop the treadmill and reconnect it at a turning speed of about 10 km / h.

Proceed to a complete test this time, continuing at higher running speeds to ensure the belt is functioning correctly without jerking.

Also read: Is it OK to Run on The Squeaky Treadmill?


To conclude, most treadmills have interchangeable rear levelling feet.

Adjusting the hind legs can help eliminate jerking when the treadmill is on uneven ground, but it cannot stop the jerking completely.

Rough surfaces can cause belt misalignment and irregular belt wear, which in turn leads to treadmill jerking.

Remember to follow the manufacturer’s user guide when fixing a jerking treadmill.