The belt coming off the deck of a riding mower is one of the biggest pet peeves of anyone who owns one. It is usually not a big deal if it slips off, and it is usually easy to replace once it falls off. When you notice your mower deck belt keeps coming off, you need to ask yourself, “why?” Because if you don’t, you’re liable to keep finding yourself on your hands and knees, and that’ll get old quickly.

You may experience Husqvarna mower belt slipping when your deck belt is worn, stretched, or shredded. If a bearing, tensioner bracket, or tensioner spring is worn, excessive vibration can cause a belt to come off your pulleys The Husqvarna Mower Belt Keeps Coming Off.

In addition to these factors, there are others that can cause a mower belt to fall off. Here’s a list of reasons that will help you figure out what belt you have

The Husqvarna mower belt keeps coming off

• Belts that are loose or worn out
• Wear and tear on the belt keeper
• The deck belt was shredded
• Bearing failure in the spindle housing
• An incorrectly aligned pulley
• Wear and tear on tensioner brackets or springs
• Interfering debris with belt tension
• Pulley grooves blocked by debris
• A belt that is oily or rusted

Belt developed oil and rust

During an oil leak in your Husqvarna mower, oil can collect on the belt and cause it to stretch if it remains there for a long time. A belt with oil on it may slip off the pulley and fall off the deck.

As well, rusty and old pulleys can cause your belt to dry out, resulting in it breaking. Start at the root if you want to fix this problem. 

It is advisable to repair the oil leak first, and then replace the rusty pulleys and the deck with a fresh belt.

Belt shredded from a Husqvarna

You may find that your Husqvarna belt becomes shredded or comes off when you are using it. It is most common for the belt to rip when it rubs against something, such as a belt keeper or bracket on the mower deck. You might also shred your belt if it isn’t properly installed.

The way your belt is routed around your pulleys may determine whether it is shredded.

You may find a decal on your mower showing how your belt must be routed or in your owner’s manual. If your belt is rubbing against any brackets or keepers, you should check for them.

If a belt rubs against a metal component, you may notice a smooth shiny spot. So that the bracket does not rub against the wall, fix it.

A bushing may need to be replaced on some brackets, or the bracket assembly may need to be replaced. This is because the manufacturer does not allow only the bushing to be changed.

Your Husqvarna pulleys have damaged Husqvarna bearings

If your pulleys are not positioned flat and parallel to your mower deck, the belt will cause vibrations. It is possible that your pulleys rest incorrectly on your deck because of worn bearings in your pulleys.

There may be a pulley side that protrudes higher from the deck than the other side. You can test a pulley’s bearing by spinning it by hand to look for a damaged or failing one.

Smoothly spinning pulleys are considered reliable pulleys. Poorly lubricated bearings will restrict the rotation of a pulley. Additionally, your bearing may make a sound that indicates your pulley needs to be replaced.

Aidleer pulleys contain sealed bearings. You must replace them all

A Husqvarna belt covered in oil or rust

During an oil leak on your Husqvarna, oil can get on the belt. This can cause the belt to swell when it is covered in oil for prolonged periods of time. The oil can cause your belt to slip on your pulleys and fall off.

Old rusty pulleys on your belt can also cause your belt to get covered in rust. Having rusted belts can cause them to dry out and crack prematurely, making your belt more likely to break.

Oil or rust coverage problems can be fixed by repairing the oil leak and cleaning the deck and pulleys. Replacement of pulleys is recommended if your pulleys are covered in rust.

Your mower deck should be replaced with a brand new Husqvarna belt after you have dealt with the items contributing to oil and rust on it.

How often should I replace the belt on my mower?

Mower belts initially have no definite life span, but the majority of mowers have short intervals between belt replacements. It is recommended that you adjust the belt once a year and replace it every two seasons. If you mow frequently in one season, you should replace it. Other parts of the system will be protected as well.

 

What is the appropriate tension for a mower deck belt?

Grab the deck belt with the tractor’s deck engaged, and twist it while it is turned off. If you twist the belt by hand, it shouldn’t move more than a quarter turn. You should tighten the belt if you can rotate it half a turn by hand.

When you turn your lawn mower off and flip the deck lever to “disengaged,” the deck belt will be much less tight.

According to Home and Garden Geek, you should be able to place one or two fingers over the same belt and gently pull it away from the pulleys. This is when the tractor is off. It corresponds to one or two pounds of force. You may have a tight deck belt if you need more than two fingers to operate it.

A second test is to turn on your mower, rev up the throttle, and then flip the deck engagement lever as fast as you can. Your blades should reach full speed within a half-second. Unless you do, your belt is too loose.

When your lawn mower deck belt has been adjusted to the maximum and it still is loose, possibly a new belt is needed.

The video below shows how to sharpen your lawn mower blades or tighten your lawn mower deck belt:

conclusion

Generally, Husqvarna deck belts are pricey so if you can extend their lifespan, the better. These items can extend the life of your The Husqvarna Mower Belt Keeps Coming Off by preventing it from prematurely wearing or breaking:

• After each mow, clean your mower deck to remove debris
• Ensure that deck components are not rubbing
• Maintain your belt to prevent rust and oil buildup
• Keep an eye out for failures in spindle housings and pulleys
• Any damaged brackets or belt keepers should be repaired or replaced