How To Center Treadmill Belt?

Tightening the treadmill too tightly can damage it for instructions on how to center a treadmill belt, and where to find the change screws, see the instruction manual. 

Use a wrench to turn the screws a quarter turn and lift the strap off the treadmill. Once the belt can be raised 2 to 3 inches, it positioned correctly the belt.

I can find instructions for removing the hood in the instruction manual. Some machines require a screwdriver to loosen the hood. Others take off.

 Pull the plug out of the device and remove the hood. Look for brands on the engine control board. 

If you find them, the resistors have blown, and the motor control board needs to be replaced. Ask the manufacturer about ordering a spare part.

Center the treadmill with the machine removed. Stand in front of the machine with one foot on the floor and the other on the belt. 

Push the belt into position with your foot by pushing it back when centering. Connect the machine and turn it on at low speed to check the belt.

 If it still doesn’t move, turn the change keys until the belt is centered.


Product Name

Speed (Max.)

Weight Capacity



11 MPH

325 lbs

84″ x 35.5″ x 58″

10 MPH

300 lbs

73"  x 36"  x 54"

12 MPH

386 lbs

84″ x 35.5″ x 58″

12 MPH

400 Lbs

84.5" x 38.5" x 54.7" 

12 MPH

309 lbs

78.8" x 39.2" x 63"

16 MPH

420 LB

83" x 35" x 62" 

Treadmill repair service

Treadmill repair, fitness equipment repair, and spare parts delivery. Our shop specializes in the supply of spare parts for treadmills and exercise bikes/ergometers, as well as replacement tapes, drive belts, treadmill motors, and control consoles. 

Fitness equipment repairs: replace the drive belt and treadmill belt

Treadmill: Replace the drive belt and treadmill belt

The best way to replace the drive belt on treadmills and other equipment:

  • Open the device
  • Remove the V-belt (push the flywheel with a screwdriver)

To make it easier to pull the V-belt on or off, the spring can also be unhooked from the holding rail for the V-belt guide rollers.


Pulling on the new V-belt:

Place the V-belt with the ribbed surface facing down on the drive wheel and pull the V-belt clockwise with the pedal’s movement.

 If the V-belt is not yet properly seated on the flywheel or the drive wheel.

It can be brought into the correct position with a screwdriver (not with the tip!). 

V-belt must run above the V-belt guide roller!

To measure the length of your tape without removing it:

  • Take a tape measure and a piece of tape

  • Stick the piece of the adhesive tape to the tape at the level of the rear roll

  • Measure the length of the engine cover and use another piece of tape to mark the location.

  • Now move the tape by hand and measure the length of the treadmill until the piece of tape comes out again.

Fitness equipment repairs: Adjusting the belt guide on Nautilus treadmills

Adjusting the belt guide on Nautilus treadmills Adjusting the belt guide (Nautilus): If the treadmill belt moves back and forth during operation, readjust the belt guide.

  • Start the treadmill at minimum speed and incline.

  • Then increase the speed to approx. 9 km / h and check whether the treadmill belt moves to the right or left.

  • If so, turn off the treadmill and disconnect it from power.

  • When the belt has moved to the right, turn the right adjusting screw 1/4 clockwise.

  • If the belt has moved to the left, turn the left adjusting screw 1/4 clockwise.

  • Reconnect the treadmill and turn it on.

  • Then let it run for 5 minutes at 9 km / h and observe whether the treadmill belt is now gliding.

  • If it still does not run optimally, repeat the above settings until the treadmill belt runs centered.

Adjust the belt tension on Nautilus Gym treadmills If the drive belt does not run properly, if the drive belt on your best treadmill for walking and light jogging slips or moves back and forth, proceed:

    • Loosen the two set screws, as shown in Figure 1.

    • Make two marks on the treadmill belt 89 cm apart. The treadmill belt must be loose enough to move on the rear rollers–see Figure 2.

    • Now turn the adjusting screws clockwise to get the same distances. In doing so, orient yourself to the markings made earlier. The correct tension for the treadmill is between 0.5 and 6%. The marking should be between 89.6 cm / 40.4 cm and 90.1 cm / 40.4 cm. Please note: The distance between the markings may not be over 90.1 cm after the tension.

    Caution: Do not tension the treadmill with too much pressure–extreme tension will damage and shorten the roller bearings.

    • Now test whether the treadmill is tensioned enough.

    • To do this, start the treadmill at a speed of 6.5 km / h.

    • Stand on the treadmill, hold the handrail lightly, and try to counter the belt’s movement with your feet (only slightly–not with force –too much resistance can cause the system to shut down)

    • If you still feel the treadmill belt sliding over the front roller, repeat the above steps, and increase the tension with a 1/2 turn of the adjusting screws.

    • Then repeat the test until the treadmill belt is optimally tensioned.

Leave a Comment