The belt is slipping

if it really is the walking belt that is slipping keep tightening the adjustment screws till the belt will not slip when you try to stop it ( set speed to about 3 and then with your foot try to stop belt from spinning - you should be able to make the motor and whole machine come to a stop ) make sure it is really walk belt spinning and it isnt the motor belt slipping. (if it is motor belt slipping when you try to do the stop the belt trick i just described you will see the walk belt and front roller stop but still hear the motor turning) once you get walk belt tight enough so it doesnt slip then you can worry about keeping the belt centered.

let me know if you need more help on this and let me know how the stop the belt test went

good luck!

Hello, It sounds like you have aslipping front roller pully. Remove the motor hood and watch the front roller while you are on it. Once the belt is moving slowly, try to stop the wlak belt by planting your fett for a second, if the walk belt stops, but the drive belt and motor continue to run, the plastic pully is slipping and the whole front roller will need to be replaced.

Hope this answers your question.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/matt_8dbc24bf722649ac

Pull the hood off. Stand on the sides of the walk platform and start the belt at 4mph. Take one foot and step on the walk belt hard. Look at the pulley on the front roller. Does the pulley continue to turn while the roller stops? If so, the pulley is slipping in the roller (which is a press fit). Replace the front roller or remove the motor belt from the pulley.Align the pulley with the pulley on the motor by tapping with a mallet. Drill an 1/8 hole throught the pulley and roller. Countersink the pulley hole so a small head screw will be under the pulley groves. Install screw in this hole. This is called pinning and is a pemanent fix. If both the pulley and the roller stop together when the belt is stepped on the motor belt is loose. If only the walkbelt stops when stepped on, the walkbelt is loose.

Before beginning this repair: Check to make certain that the drive belt requires adjustment. Check out belt slipping instructions or with the motor cover removed, walk on the belt normally and try to stall the belt to make it slip. Be careful during this test. If the problem is in the drive belt, either the drive belt will stop when stalled or the front roller will stop when stalled. If the motor, drive belt, and front roller continue to turn when the walking belt is stalled, the problem is with the walking belt slipping on the front roller. If the drive belt continues to turn but the front roller stalls, you may have a broken front roller pulley.
Step 1- Find the motor mounts. Many motors in Icon treadmills have a main pivot joint in which a bolt runs the full length of the motor mount. This bolt will require loosening to provide maximum adjustability. Some models have a single jack bolt and others have an auto tensioner. Single jack bolts are the easiest to adjust. Step 2- Find the set bolt(s) on the motor. This is typically run through only one side of the motor mount or may be on both sides but it does not run the full length of the mounting. Loosen this bolt(s) but do not remove. Jack bolt models will have flat mounts and may contain up to four bolts. Step 3- Look for a bolt that will tension the motor. If it has this bolt, it typically runs in the same direction parallel with the drive and walking belts. If your treadmill is not equipped with this bolt, skip to Step 4. If your treadmill is equipped with this bolt (very few are) the repair will only require one person. Using 2 7/16" wrenches, make a few turns to this bolt, tighten the bolts from Steps 1 and 2 and test your treadmill for slipping. If belt continues to slip, repeat Steps 1, 2, & 3. If a second attempt does not repair the problem, skip to Step 5. Step 4- If your treadmill is not equipped with a bolt as described in Step 3, the drive belt must be tensioned by hand. While one person applied increased tension to the drive belt, the other person should tighten the motor set bolt(s) that are described in Step 2. Tighten the bolt from Step 1 and test. If the problem is not corrected, repeat Steps 1, 2, & 4 and retest. If problem persists, skip to Step 5. Step 5- If you have arrived at this step, let's make sure you have a drive belt tension problem. With the motor cover removed, walk on the belt normally and try to stall the belt to make it slip. Be careful during this test. If the problem is in the drive belt, either the drive belt will stop when stalled or the front roller will stop when stalled. If the motor, drive belt, and front roller continue to turn when the walking belt is stalled, the problem is with the walking belt slipping on the front roller. the problem. Another possibility is that the drive belt has worn down. In some cases, belt dressing may help correct the problem. If not, the drive belt must be replaced. Step 6- The belt should be able to be turned by hand at approximately a 90 degree angle from its normal operating position

Unplug unit remove motor shroud then plug unit back in , press start and begin walking on the belt normally and try to stall the belt to make it slip ( planting foot to stop the belt).
Be careful during this test. If the problem is in the drive belt, either the drive belt will stop when stalled or the front roller will stop when stalled. Here is the procedure for adjusting the drive belt.
Find the motor mounts. Many motors in Icon treadmills have a main pivot joint in which a bolt runs the full length of the motor mount. This bolt will require loosening to provide maximum adjustability. Some models have a single jack bolt and others have an auto tensioner. Single jack bolts are the easiest to adjust.
Find the set bolt(s) on the motor. This is typically run through only one side of the motor mount or may be on both sides but it does not run the full length of the mounting. Loosen this bolt(s) but do not remove. Jack bolt models will have flat mounts and may contain up to four bolts.
Look for a bolt that will tension the motor. If it has this bolt, it typically runs in the same direction parallel with the drive and walking belts. If your treadmill is not equipped with this bolt, skip to Step 4. If your treadmill is equipped with this bolt (very few are) the repair will only require one person. Using 2 7/16" wrenches, make a few turns to this bolt, tighten the bolts and test your treadmill for slipping. If belt continues to slip, and if their is too much tension ( you should be able comfortably twist the drive belt 90 degrees ) then replace drive belt. If the motor, drive belt, and front roller continue to turn when the walking belt is stalled, the problem is with the walking belt slipping on the front roller, here the procedure adjusting the walking belt.
If the walking belt slips when walked on, first remove the key and UNPLUG THE POWER CORD. Using the allen wrench, turn both rear roller bolts clockwise, 1/4 of a turn.When the walking belt is correctly tightened, you should be able to lift each side of the walking belt 3 to 4 inches off the walking platform. Be careful to keep the walking belt centered. Plug in the power cord, insert the key and carefully walk on the treadmill for a few minutes. Repeat until the walking belt is properly tightened
If the drive belt continues to turn but the front roller stalls, you may have a broken front roller pulley. If this is the problem, you will notice it because the plastic will usually make a loud squealing sound on the metal front roller. The front roller assembly will need to be replaced and the drive belt must be replaced also. We suggest replacing the drive belt as well because it is a low cost item and will most likely, have suffered unusual wear from the problem. Another possibility is that the drive belt has worn down. In some cases, belt dressing may help correct the problem. If not, the drive belt must be replaced.

Hi James
Unplug unit remove motor shroud then plug unit back in , press start and begin walking on the belt normally and try to stall the belt to make it slip ( planting foot to stop the belt).
Be careful during this test. If the problem is in the drive belt, either the drive belt will stop when stalled or the front roller will stop when stalled. Here is the procedure for adjusting the drive belt.
Find the motor mounts. Many motors in Icon treadmills have a main pivot joint in which a bolt runs the full length of the motor mount. This bolt will require loosening to provide maximum adjustability. Some models have a single jack bolt and others have an auto tensioner. Single jack bolts are the easiest to adjust.
Find the set bolt(s) on the motor. This is typically run through only one side of the motor mount or may be on both sides but it does not run the full length of the mounting. Loosen this bolt(s) but do not remove. Jack bolt models will have flat mounts and may contain up to four bolts.
Look for a bolt that will tension the motor. If it has this bolt, it typically runs in the same direction parallel with the drive and walking belts. If your treadmill is not equipped with this bolt, skip to Step 4. If your treadmill is equipped with this bolt (very few are) the repair will only require one person. Using 2 7/16" wrenches, make a few turns to this bolt, tighten the bolts and test your treadmill for slipping. If belt continues to slip, and if their is too much tension ( you should be able comfortably twist the drive belt 90 degrees ) then replace drive belt.
If the motor, drive belt, and front roller continue to turn when the walking belt is stalled, the problem is with the walking belt slipping on the front roller, here the procedure adjusting the walking belt.
If the walking belt slips when walked on, first remove the key and UNPLUG THE POWER CORD. Using the allen wrench, turn both rear roller bolts clockwise, 1/4 of a turn.When the walking belt is correctly tightened, you should be able to lift each side of the walking belt 3 to 4 inches off the walking platform. Be careful to keep the walking belt centered. Plug in the power cord, insert the key and carefully walk on the treadmill for a few minutes. Repeat until the walking belt is properly tightened
If the drive belt continues to turn but the front roller stalls, you may have a broken front roller pulley. If this is the problem, you will notice it because the plastic will usually make a loud squealing sound on the metal front roller. The front roller assembly will need to be replaced and the drive belt must be replaced also. We suggest replacing the drive belt as well because it is a low cost item and will most likely, have suffered unusual wear from the problem. Another possibility is that the drive belt has worn down. In some cases, belt dressing may help correct the problem. If not, the drive belt must be replaced.

If the problem is in the drive belt, either the drive belt will stop when stalled or the front roller will stop when stalled. If the motor, drive belt, and front roller continue to turn when the walking belt is stalled, the problem is with the walking belt slipping on the front roller. If the drive belt continues to turn but the front roller stalls, you may have a broken front roller pulley.
Find the motor mounts. Many motors in Icon treadmills have a main pivot joint in which a bolt runs the full length of the motor mount. This bolt will require loosening to provide maximum adjustability. Some models have a single jack bolt and others have an auto tensioner. Single jack bolts are the easiest to adjust.
the drive belt must be tensioned by hand. While one person applied increased tension to the drive belt, the other person should tighten the motor set bolt(s)

Most likely it is the Drive belt from the motor to the front roller, remove the motor hood, get it going at 3.0 mph and hold on to the rails, then put your foot forward and down pretty hard and see if it slips on the motor pulley, if so it's time for a new drive belt or an adjustment to it.