Murray Riding Mower Belt Keeps Coming Off

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If your Murray riding mower belt keeps coming off, it may be because of a worn belt or defective belt keepers.

In this article, I share 13 reasons why the Murray riding mower belt keeps coming off and proven fixes to solve the issue and get your mower working efficiently again.

Reasons Your Murray riding Mower Belt Keeps Coming Off

Some of the reasons why your Murray riding mower belt keeps coming off include:

  • Worn or loose belt
  • Rust or oil on the belt
  • Loose pulleys
  • Damaged pulley guard
  • Worn spring or idler tensioner bracket

Tools You Need For This Job

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

  • A pair of safety gloves
  • Hammer
  • Vice grips
  • Adjustable wrench 
  • A set of pliers
  • New belt
  • Woodblocks

Murray Riding Mower Belt Keeps Coming Off: Possible Causes And Fixes

1.  Damaged or Loose Belt

A loose or damaged mower belt may be the reason why your belt keeps coming off. 

If it is worn or broken, it can fly off at a high velocity while the engine is running. This can cause an injury to the operator.

Diagnosis

Inspect the belt for damage, frays, cracks, and looseness. If you detect these signs, it means that you need to replace them.

Fix

It is best to replace the old belt with a new one. 

How To Change The Belt On a Murray Riding Lawn Mower

Here are some tips on how to change the belt on a Murray riding lawn mower:

Step One: Gather the Required Tools

The first step to take is to gather the required tools. Placing a new belt on your mowing machine is not a tedious task.

You will need tools such as woodblocks, an adjustable wrench, a pair of safety gloves, screwdrivers and a set of pliers.

Step Two: Check the Part Number for the Replacement

It is also important to read the user manual to get more information about the part number of your replacement belt.

Check the current belt markings if you can’t find the part number in the user manual. Make sure that the belt has the correct shape and length.

Step Three: Park Your Murray Riding Mower at a Proper Place

Park your mowing machine on a level and flat surface that is ideal for your work. Ensure that you set the parking brake after switching off your mower engine.

Before moving the blade rotation control to the “disengage” position, you need to set your mower housing to the lowest position. Remove the boot from the spark plug’s end

Step Four: Extract the Hairpins

Inspect the chassis of the mower and disconnect your rear suspension arms. Take off the hairpins from the arms. .

You should also make sure that you take off the washers. Furthermore, remove the arms from the pins of the chassis and set the washers and hairpins aside in a secure spot.

Step Five: Unhook the Extension Spring

Remove the washers and the hairpins from the suspension links. 

Furthermore, take off the links from the mower chassis support and remove the extension spring that is linked with the blade control rod.

Step Six: Take Off the Front Hanger

Always remember to take off the front hanger from the chassis support. Pull the hairpin and washer that are located at the end of the connecting end rod.

Remove this rod and detach the hanger from your mower’s chassis.

Turn the pulley of the engine and roll off the blade drive belt. Slide the cutting deck out from underneath the chassis of the mower.

Step Seven: Take Out the Mower Belt

Remove the belt retainer away from the idler pulley and slowly take out your mower belt. Detach the mower belt from the jackshaft pulley.

To remove the belt, you need to pull the brake pad back.

Step Eight: Install the New Mower Belt

For proper installation, pull the back of the brake pad and connect the belt to the jackshaft pulley.

Mount your belt on the mower’s idler pulley after pulling the retainer back and align the belt so that the “V” side will be in the pulley’s center.

Step Nine: Connect Your Belt to the Mower Engine

Center the mower housing by sliding it underneath the chassis. After that, reattach the mower belt to the engine pulley in a secure manner.

With the holes in the chassis support, ensure that you line up the holes within the front hanger.

Put the connecting rod through the holes and fasten it with a washer and hairpin.

Step Ten: Connect the Suspension Links

Attach the mower’s extension spring to the blade control rod. Carefully connect the suspension links to the mower chassis supports and use washers and hairpins to secure them.

Put the mower’s rear suspension arms to the chassis. Raise your mower housing and connect your spark plug cable back to the spark plug’s tip.

2. Damaged Belt Guide 

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

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

Diagnosis

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

Fix:

  • Use vice grips or a hammer to bend the belt guide back in place.
  • Replace the belt guide if it is in bad condition.

3. Shredded Belt

The shredded or defective Murray riding belt can affect the functionality and performance of the mower.

In this situation, the belt will become weak and may break, causing the belt to come off the deck of your lawn mower. It can also shred if the belt is not properly installed.

Diagnosis

  • Check the belt edges for signs of shredding and inspect if the belts are rightly routed around the pulleys.
  • If the belt is properly routed, inspect if the part of the belt guide makes contact with the deck belt.
  • If you notice a shiny or smooth spot on the metal, then the belt is shredded.

Fix

  • Check your owner’s manual to confirm if the belt is rightly installed.
  • It might be possible to bend some of the brackets to their place. Some brackets can also require a bushing replacement. Brackets that come with bushings may only be available for purchase as a bracket assembly.  In this case, you need to contact a Murray riding dealer to help you to find the parts that are ideal for your mower deck model. 
  • Adjust or repair the shredded belt

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.

Diagnosis

  • 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.

Fix

  • Replace the bad spindle housing.

5. Idler Tensioner Bracket or Spring is Worn

The bracket is responsible for holding idler pulleys in line. If the spring is weak, the mower’s belt may come off.

In addition, the tensioner bracket’s hole where the spring attaches may deteriorate and enlarge with use, causing excessive vibration in your mowing machine.

Diagnosis

  • Locate the pulley on one side of the bracket and the spring on the other side.
  • If the spring appears weak or the tensioner bracket (where the spring attaches) is worn, it needs replacement.

Fix

  • Replace the worn 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 Murray riding 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.

Diagnosis

  • 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. 

Fix

  • 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. Rust or Oil on Your Murray Riding Mower Belt

Rust or oil on the belt can cause it to come off the lawn mower. If oil is left on the belt for an extended time, the belt may swell.

An oil leak may cause oil to get on the belt and can result in belt slippage on the pulleys.

Old brackets and pulleys may develop rust that can get on the deck belt. This causes the belt to crack, dry out or break.

Diagnosis

  • Check if the brackets and pulleys are rust-free.
  • A low oil level may indicate that you have an oil leak.

Fix

  • Ensure that the brackets and pulleys are rust-free. 
  • Replace rusty pulleys and inspect the oil level before carrying out mowing operations.
  • Replace the mower deck belt once you have fixed the issue of oil and rust.

8. Debris in the Grooves of Your Murray Riding Mower 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.

Diagnosis

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

Fix

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

9. Debris Interfering with Proper Tension on The Murray Riding Mower Belt

It is important to keep the deck free of debris. Your Murray riding mower belt can become loose and fall off if the debris interferes with the proper tension on the belt.

This interference can cause the tensioner not to move and create proper tension on the belt. This can cause the belt to become loose and may fall off.

Diagnosis

  • You need to check the mower deck for debris.

Fix

  • Keep the deck clean.

10. Murray Riding Mower Deck Belt Breaks or Gets Heated Up

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

Diagnosis

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

Fix

  • 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 Murray riding 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.

Diagnosis:

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

Fix

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

12. Damaged Pulley Guard

The pulley guards help to keep the mower belt on the pulley. If it is damaged, it can affect the functionality of your mower.

Diagnosis

  • Check if the pulley guards are defective. If they are defective, they won’t be able to keep the belt on the mower pulleys.

Fix

  • Replace the pulley guards. If the problem persists, it is best to replace your pulleys. 

13. 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.

Diagnosis

  • 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.

Fix

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

Tips to Extend The Lifespan of Your Murray Riding Mower Belt

Here are some tips to follow to elongate the life of your Murray riding mower belt:

  • Replace damaged belt keepers or brackets.
  • Always clean your mower’s 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.

Conclusion

Several factors such as damaged belt guides, worn belt, loose pulleys, damaged pulley guards and oil or rust on the belt may cause your Murray riding mower belt to come off.

Follow the troubleshooting guide to solve the issue. If you have tried these troubleshooting tips and the problem persists, it is best to seek the help of a professional to fix the problem.