Why Is My Treadmill Skipping

If you’ve noticed a jerking motion during your run, you’re probably wondering why is my treadmill skipping. This frustrating issue can interrupt your workout and might even be a sign that something needs fixing. Don’t worry, though—it’s a common problem with a set of common causes that you can often fix yourself.

A skipping treadmill belt feels like it’s slipping or jerking under your feet. It’s not just annoying; it can throw off your balance and is a clear signal that your machine needs some attention. This skipping happens when the belt loses it’s proper grip on the deck or the drive system.

Main Reasons Your Treadmill Belt Skips

Several factors can cause this problem. Usually, it boils down to simple wear and tear or adjustments that have come loose over time. Here are the most frequent culprits:

A Loose Walking Belt: This is the number one cause. Over time, the belt stretches and needs to be tightened.
Poor Lubrication: The belt needs to slide smoothly over the deck. Without proper lube, friction increases and causes sticking and skipping.
A Worn or Damaged Belt: Cracks, fraying edges, or stretched areas can prevent smooth movement.
Misaligned Belt: If the belt has shifted to one side, it won’t track correctly and can slip.
A Worn Drive Belt: This is the internal belt that connects the motor to the roller. If it’s loose or glazed, it can’t transfer power properly.
Failing Motor or Motor Controller: If the motor’s power output is inconsistent, it can cause the belt to jerk.

How to Fix a Skipping Treadmill: A Step-by-Step Guide

Before you start any repair, always unplug the treadmill from the wall outlet for safety. Never work on a powered machine.

Step 1: Check and Tighten the Walking Belt

First, perform the “lift test.” Try to lift the edge of the belt from the middle of the deck. You should be able to lift it about 2 to 3 inches. If you can lift it higher, it’s too loose.

Locate the two adjustment bolts at the rear of the treadmill. They are on the left and right side near the back roller.
Using the correct hex wrench (usually provided with the treadmill), turn both bolts a quarter-turn clockwise. Always adjust both sides equally to keep the belt centered.
Recheck the tension with the lift test. Repeat until the tension is correct. Don’t overtighten, as this can strain the motor.

Step 2: Lubricate the Treadmill Deck

If tightening didn’t help, or if the belt seems dry, you need to lubricate. Most modern treadmills require silicone-based lubricant. Check your manual for the specific type.

Loosen the belt slightly using the rear adjustment bolts, so you can access the deck underneath.
Apply the lubricant in a thin, zig-zag pattern along the entire length of the deck, under where the belt runs. Avoid using to much.
Retighten the belt to the proper tension.
Plug in the treadmill and run it at a slow speed for 2-3 minutes to spread the lubricant evenly.

Step 3: Check the Belt Alignment

A misaligned belt will often rub against the side rails. To check, run the treadmill at a slow speed and watch the belt. It should be centered between the side rails.

If the belt drifts to the left, slightly tighten the left adjustment bolt OR loosen the right one (quarter-turn increments).
If it drifts to the right, slightly tighten the right bolt or loosen the left one.
Let the belt run for a minute after each adjustment to see if it corrects. This process requires patience.

Step 4: Inspect the Walking Belt and Deck for Wear

Look closely at the belt’s surface and edges for signs of damage. Also, feel the deck surface for any grooves, warping, or burned spots. A badly worn belt or a damaged deck will need to be replaced for a smooth ride. If you see shiny, glazed spots on the belt underside, it’s a sign of excessive friction.

Step 5: Inspect the Internal Drive Belt

For this step, you’ll need to remove the motor hood. Consult your manual for how to do this safely for your model.

Locate the drive belt connecting the motor pulley to the front roller pulley.
Check its tension—it should have a little give, about half an inch of flex when pressed.
Look for cracks, fraying, or a shiny, glazed appearance. A glazed belt has lost it’s grip.
If the drive belt is damaged or loose (adjustment varies by model), it will need replacement.

When to Call a Professional Technician

Some problems are best left to the experts. Consider calling for service if:

The belt still skips after you’ve tried all adjustments and lubrication.
You hear grinding, loud buzzing, or smell burning from the motor area.
The console shows error codes related to the motor or speed sensor.
The treadmill jerks or the speed fluctuates wildly on it’s own.
You’re not comfortable performing internal inspections.

Preventing Future Skipping Problems

Regular maintenance is the key to a long-lasting, smooth-running treadmill. Follow this simple routine:

Clean Regularly: Wipe down the belt and deck area after workouts to remove dust and sweat.
Lubricate on Schedule: Follow the manufacturer’s guideline, usually every 3-6 months or every 130 miles.
Check Tension Monthly: Give the belt a quick lift test every few weeks.
Balance Usage: Try not to always run in the exact same spot on the belt.
Plug Directly into a Wall Outlet: Avoid using extension cords, which can cause power drops that affect the motor.

FAQ: Common Treadmill Skipping Questions

Q: Why does my treadmill skip when I first start it?
A: This often points to a loose drive belt or a motor that’s struggling to provide consistent torque from a cold start. It could also be a sign of a aging motor capacitor.

Q: My treadmill only skips when I’m running, not walking. Why?
A: This is a classic sign of a belt that is just slightly too loose. The extra force of your run is causing it to slip on the roller, whereas walking doesn’t provide enough force to cause the skip.

Q: Can a dirty speed sensor cause skipping?
A: Yes. If the sensor on the front roller or the magnet it reads is dirty, it can send erratic speed data to the controller, causing the motor to pulse and jerk, which feels like the belt is skipping.

Q: I just lubricated it, but now it’s skipping worse. What did I do wrong?
A> You might have used to much lubricant. Excess lube can cause the belt to hydroplane and lose traction. Wipe away any visible excess and run the belt slowly to help it distribute evenly.

Q: Is a skipping belt dangerous?
A: It can be. The sudden jerk can cause you to lose your balance and fall. It also indicates mechanical stress that could lead to a bigger, more expensive breakdown. It’s best to adress the issue promptly.

Figuring out why your treadmill is skipping is usually a process of elimination. Start with the simplest fixes—belt tension and lubrication—as these solve the vast majority of cases. Regular care is your best defense against this annoying problem, ensuring your machine stays reliable for the long run. With these steps, you can likely get your workouts back on track smoothly and safely.