Husqvarna Riding Mower Belt Keeps Coming Off

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If your Husqvarna riding mower belt keeps coming off, it may be because of a damaged belt guide or a worn idler tensioner bracket.

In this article, I share 12 possible reasons why the Husqvarna riding mower belt may keep coming off. And some proven and tested fixes to help you solve the problem.

Contents show

Reasons Your Husqvarna Mower Belt Keeps Coming Off

Some of the reasons why your Husqvarna mower belt might keep coming off include:

  • Worn or loose Husqvarna belt
  • Shredded belt
  • Damaged belt keeper
  • Faulty bearing in the spindle housing
  • Worn idler tensioner bracket or spring

Tools You Need For This Job

While troubleshooting, you might need to have the following tools nearby:

  • Work gloves
  • Hammer
  • Vice grips
  • Clean cloth
  • Socket wrench 
  • New belt

Husqvarna Mower Belt Keeps Coming Off: Possible Causes And Fixes

1. Worn or Loose Husqvarna Belt

Over time, the belt of your Husqvarna mowing machine may wear due to continuous use and exposure to different conditions. This can cause it to become loose and come off in the process.


  • Inspect the pulleys and their bearings. If they are not in place, it indicates that they are not correctly positioned.
  • If there is a cracked or shiny appearance on the belt, it indicates that the belt is worn.


  • Replace the belt if it is worn or loose.

How to Change a Deck Belt on a Husqvarna Riding Lawn Mower


Here are some tips on how to change the deck belt of your Husqvarna riding mower:

Step One: Prepare the Mower For Service

Park and Brake the Mowing Machine

It is important to park the lawn mower on a level and solid surface. Press down on the brake pedal and set the parking brake.

Disengage the Clutch

Move the attachment clutch to the “disengaged” position. Turn the mower off and take off the key from the ignition.

Disconnect the Mower’s Spark Plug Cables

After the blades have stopped moving, disconnect the spark plug wires and set the wire away from the plug.

Step Two: Removing the Mower Deck

Position the Deck of the Husqvarna Riding Mower

You need to put the mower deck in its lowest position.

Take Off the Belt

Roll the belt down over the pulley edge to remove the deck belt from the electric clutch pulley that is attached to the body of the mower.

Extract the Retainer Pins

Take off the retainer pins from the anti-sway bar that is on the deck opposite the electric clutch pulley.

Remove retainer pins from both suspension arms located between the anti-sway bar and the electric clutch pulley..

You should also remove the retainer pins from the front link arms that connect the deck’s side to the mowing machine.

Reposition the Mower Deck Lift Lever

Ensure that you move the deck lift lever to its highest position.

Remove the Cutting Deck

Slide the cutting deck from underneath the mowing machine.

Step Three: Replace Your Deck Belt

Take Note of the Positions of the Pulley And Belt

It is important to take note of the way the belt is threaded around the pulleys. You can draw a picture or take a photo of it so that you will be able to get how to thread the new belt.

Take Off the Old Belt

You can now take off the old belt from the belt path.

Thread the New Belt Onto the Pulleys

Put the new one in the belt path around the outer part of the two largest outer pulleys. 

Thread your belt in the forward position so that it can go between the outer and inner sets of your pulleys and can come out between the two inner pulleys.

If you didn’t take off the deck, you can pull the looped end of your belt around the electric clutch pulley. Otherwise, you may leave the looped end loose until your mower deck is changed underneath the mowing machine.

Check the Alignment

Ensure that you inspect if the belt is correctly seated in the belt path of all five pulleys.

Step Four: Install the Mower Deck

Raise your Mower Deck

Make sure that you raise the mower deck in its highest position.

Slide the Mower Deck Underneath the Mowing Machine

Slide your deck underneath the lawn mower. The opening where the grass is ejected should be on the right side of the mowing machine

Move The Lever

You should move your lever to the lowest position.

Reinstall the Bars

Make sure that you reconnect all the disconnected bars when you remove the mower deck and replace all the retainer pins.

Seat the Belt

Pull the looped end of your deck belt over the electric clutch pulley and make sure that it is correctly seated in the grooved belt path. 

Reconnect your spark plug cables after you have finished servicing the mowing machine.

Please note: Ensure that you refer to the owner’s manual because there might be slight variations in belt replacement among Husqvarna models.

If you take off your cutting deck, make sure that you follow the instructions in the mower’s manual for the proper procedure to level the blades after installation. 

2. Shredded Belt

Your Husqvarna mower belt may become shredded and can break or come off the mower deck. 

Shredding can happen when the belt rubs against an object such as a bracket or belt keeper on the deck. The belt can also shred if you do not install it properly.


  • Check if the belt is properly routed around the pulleys.
  • Inspect if the belt isn’t rubbing itself against the belt keepers or brackets. A shiny appearance or smooth spot is an indication that the belt is rubbing itself on a metal component.


  • You may replace the bushing on some brackets. If you can’t replace the bushing, you may need to change the bracket assembly. 

3. Damaged Belt Keeper 

The function of belt keepers is to keep the belt in place. Although your belt won’t touch the keepers, they protect the belt from slipping off the pulleys. 

They can become bent and defective, allowing the belt to come out of place.


  • Inspect if there is slack in the belt. If you notice an extra slack, the mower’s belt guides may move out of place.


  • Use vice grips or a hammer to bend the belt keeper back in place.

4. Faulty Bearing in The Spindle Housing

It is also important to check any bad bearing in the spindle housing if the belt keeps coming off.

A defective bearing in the spindle housing can make your cutting deck vibrate when you engage the blades. This vibration can cause the belt of your mowing machine to come off.


  • The first step to take is to get work gloves to shield your hands from the blades’ sharp cutting edges.
  • Rock the blade in an upward and downward position by grabbing hold of each end. While rocking the blade, check for any movement. If you notice a movement or you hear a knocking noise, it indicates that the bearing in the housing may be defective.


  • Replace the bad spindle housing.

5. Worn Idler Tensioner Bracket or Spring 

It is always important to check the idler tensioner bracket or spring if your mower belt keeps coming off.

The spring may be weak and the hole in the tensioner belt can also become larger and worn. This can cause the mower belt to fall off and affect the mower’s performance.


Check for worn idler tensioner brackets and the weak spring. If you notice signs of vibration in the mower, it means that you should replace the worn parts


Replace worn idler tensioner bracket or spring.

6. Bad Bearing in the Pulley

Bad bearings in the pulleys may cause the pulleys not to sit parallel and flat to your Husqvarna lawn mower deck.

In this situation, the sides of the pulley may be higher than the other. This will make the mower belt not to run properly and can come off the pulley.


  • Rotate each pulley by hand to check for a bad bearing. Move them slowly to be sure that they are turning smoothly.
  • Check if you can hear a noise emanating from the bearing or if you feel any restrictions. If you detect these signs, then the bearing is bad. 


  • Replace the bearing in some pulleys. 
  • If you notice a bad bearing in an idler pulley, replace the entire pulley because it contains a sealed bearing.

7. Oil and Rust on Husqvarna Belt

Oil can get onto the belt and cause it to stretch if the oil covers it for a long period, causing oil leakage. If the oil is covered on the belt, it can cause it to slip on the belts and come off your mower deck.

Another reason for this issue is rusty and old pulleys. These rusty pulleys can cause the belt to dry out, making it liable for breakage.


  • Check your mower for oil on the belt and rusty pulleys.


  • Repair the oil leak
  • Change the rusty pulleys and also replace the mower deck with a new belt. 

8. Debris in the Grooves of Your Husqvarna Pulleys

The grooves in the pulleys collect mud or debris that can cause the belt to come off your lawn mower.

The pulley’s material may also cause the belt to stretch and this will allow it to snap or roll off the pulley.


  • Take a look at the grooves in the pulley and check for items (such as debris and mud) that are stuck in the area.


  • Examine the grooves in the pulley and take off any items that may be stuck in this area.

9. Debris Interference

The debris can accumulate around the tensioner and pulleys of your mower. This can hinder the proper movement of the pulley and can loosen the belt if it does not get enough tension. In this case, the belt can vibrate.

Debris build-up can also cause fire hazards due to the heat of the belt.


  • Check the belt for excessive vibration. If it vibrates, it can be a result of debris buildup.


  • Take off the debris thoroughly and clean it with a clean cloth. 

10. Husqvarna Mower Deck Belt Breaks or Gets Heated Up


This is one of the problems that can be associated with your Husqvarna lawn mower belt. If the belt breaks, it will come off the mower deck.


  • If you detect unsatisfactory cuts, turn off the engine of your Husqvarna mower and check the mower deck carefully for any sign of belt breakage.


  • To fix a broken belt, you need to clean your mower deck, adjust the pulleys and replace the belt.

11. Extreme Weather And Temperature Can Cause The Belt To Come Off

Your Husqvarna mower belt may keep coming off in extreme temperature changes. This issue is very common in very cold climes.

The reason is that the belt loses its shape in cold weather. If you continue to operate the mowing machine with this problem, It will produce cracks on the belt and break it.


  • Check for cracks on the belt to know if the belt is damaged. 


  • Do not operate the mower in extreme temperatures and weather. 
  • Replace the cracked belt with a new one.

12. Loose Pulleys

The belt connects a series of pulleys in the mower deck, which enables the mower blades to engage and spin.

If the pulleys are loose, the entire system would be compromised if the pulleys become loose in their positions.


  • Check the pulleys if they are not loose in their positions
  • Examine other parts of the pulley-belt system. If the parts are damaged or lost over time, it means that the pulleys are loose and the mower belt won’t stay in place.


  • It is advisable to seek the help of a trusted mechanic that can check the Husqvarna mower for defective or missing rear hanger clip pins and draft rods.

Tips to Extend The Lifespan of Your Husqvarna Mower Belt

Here are some tips to follow to elongate the life of your Husqvarna lawn mower belt:

  • Replace damaged belt keepers or brackets.
  • Always clean your Husqvarna cutting deck after mowing to get rid of debris.
  • Inspect the spindle housings and pulleys for bearing failure at periodical intervals.
  • Keep rust and oil from forming on your belt.


Some of the possible reasons why your Husqvarna riding mower belt keeps coming off include shredded belt, loose pulleys, faulty bearing in the spindle and loose or worn belt.

I hope these recommended fixes will help you solve the issue. If you have tried these troubleshooting tips and the problem persists, it is advisable to call the technician.