10 Reasons Why Your Cub Cadet Belt Keeps Coming Off or Breaking? – Expert Guide

From stuck blades to frayed belts, Cub Cadet lawn mowers can have a variety of problems that can leave you perplexed. If your Cub Cadet belt keeps coming off or breaking – don’t worry! You’re not alone here. In this blog post, we’ll be exploring the most common causes behind why a Cub Cadet belt might come loose or break and provide specific tips on how to fix them.

The Cub Cadet mowers are notorious for poorly designed belt-deck configurations. The Idler Pulley Brackets are inadequately supported with springs leading to excessive vibration combined with a misalignment of the pulleys will lead to eventually the belt popping off of the deck and/or being cut by the pulleys themselves.

Whether it’s tension-related issues or worn components that need replacing, our step-by-step guide will make sure your lawn mower is running smoothly again in no time. Keep reading to learn all about ten potential reasons why your Cub Cadet belt isn’t working properly and what you can do about it.

What causes belt to come off of cub cadet mower?

There are many reasons why your Cub Cadet belt may be coming off. Here are some of the most common culprits:

1. Loose or Worn Cub Cadet Belt

Although it may not be obvious at first glance, your belt – just like all of us – can become worn with time. To make sure you’re getting the most out of its durability and power, keep an eye on how snugly it fits. If the fit is starting to loosen or show signs such as a shiny surface from normal use or even small cracks, then consider changing that Cub Cadet belt for more reliable performance!

2. Cub Cadet Belt Keeper Damage

The belt keeper is a metal piece that helps keep the belt in place and can suffer wear or tear over time. If the belt keeper looks worn or misshapen, you should replace it, as this could be causing your cub cadet xt1 belt keeps coming off. The keepers sit about 1/8” to 1/4” away from the pulley so your Cub Cadet belt shouldn’t be rubbing against it. Sometimes it is easy to bend the keeper back into place using a hammer or other tool. If that doesn’t work, you should replace it.

3. Shredded Cub Cadet Belt

If your lawn mower belt is shredded and you can’t find the cause, it could be that something is preventing the belt from routing around necessary components of the deck. This might include a particular component rubbing against it or the belt being installed incorrectly.

To identify what’s causing the issue, take a look at where your belt travels and be sure to check all pieces of metal on your deck for telltale signs of wear and tear. If you find that there’s an old bushing in a bracket, replacing it may do the trick.

But if not, you may need to replace the whole bracket assembly altogether. In any case, taking some time to figure out what’s going on with your belt before replacing it will go a long way towards keeping your lawn mower trusty and ready to go when you need it.

4. Damaged Bearings in Your Cub Cadet Pulleys or Spindle Housings

If you have a Cub Cadet with a shaft-driven deck, then the pulleys or spindle housings may be worn and need replacement. If so, it’s likely causing your belt to slip off due to misalignment or incorrect tension. To assess if this is the case, remove your old belt and inspect each of the pulleys for signs of wear and tear. If you find that the bearings are worn, consider replacing them with new ones.

Your issue may be with the spindle housing assembly. A common cause of belt slips is the bearing in the spindle housing being worn. To check, remove your mower’s belt and inspect the spindle housing for signs of wear. 

To check your housing, make sure you’re wearing a good pair of work gloves so you don’t cut yourself on the sharp blades. Also, make sure the ignition key is removed and the spark plug boots are removed for safety.

Grab a hold of each side of the blade and rock the blade up and down. Listen closely for a knocking sound. You’re also feeling for any movement when rocking the blade.

If you find either one of these symptoms of a damaged spindle housing, you’ll have to take the spindle housing apart and check for a bad bearing or other problem in the housing.

Some spindle housings are sealed and the whole assembly must be replaced while others can be rebuilt.

5. Cub Cadet Idler Tensioner Bracket or Spring is Worn

The Cub Cadet idler tensioner bracket or spring is responsible for keeping the belt tight, and if it’s worn or broken then the belt can come loose. Check your idler tensioner bracket or spring to make sure it’s in good condition and replace any broken components you find. You have to get the cub cadet drive belt tension spring diagram to help you. You can get it from your local Cub Cadet dealer or online.

The hole in the bracket where the spring is attached can become worn or the spring itself can become worn. When this happens, a vibration is created that can make your cub cadet ltx 1050 belt keeps coming off.

6. Debris Interfering with Proper Tension on Your Cub Cadet Belt

Debris or an obstruction on or near your cub cadet rzt 50 deck belt keeps coming off

. Anything from leaves and grass clippings to sticks and stones can get stuck underneath the belt and interfere with its tension. The best way to check for this is by turning your machine over on its side and inspecting the area beneath the belt for any obstructions.

7. Debris in Grooves of Your Cub Cadet Pulleys

Your pulleys can collect debris, like stones and wood chips, that may get caught in the grooves or under the pulley. Something as simple as a single piece of debris can cause the belt to slip, so be sure to check all your pulleys for any signs of obstruction. If you find anything blocking the path of the belt, remove it and reinstall the belt on your Cub Cadet. 

8. Oil on Your Cub Cadet Belt

Oil or other lubricants can also cause your cub cadet xt1 belt keeps coming off. Oil has a lubricating effect on the belt, making it less likely to grip the pulleys properly when tension is applied. If you find oil on your belt, use a cloth and some detergent to wipe it off before reinstalling your belt.

9. Rust on Your Cub Cadet Belt

Rust can also cause your cub cadet pto belt keeps coming off. Rust forms as a result of moisture and dirt building up on the belt and this can make it less effective at gripping onto pulleys. To fix this, use a wire brush or steel wool to scrub away any rust that has built up on the belt before reinstalling it.

10. Misalignment or Incorrect Tension on Your Cub Cadet Belt

Misalignment or incorrect tension can also cause the belt to slip off your Cub Cadet. Make sure that all of the pulleys are properly aligned and that there is enough tension on the belt, but not too much. To check for this, use a torque wrench to measure the tension and adjust if necessary.

How To Take Care of My Cub Cadet Mower?

Following these steps will help extend the life of your Cub Cadet belt and keep it from falling off:

  • Clean your mower deck after each mowing to remove debris, clippings and other obstructions that may be preventing the belt from gripping the pulleys properly.
  • Periodically check for any signs of wear and tear on the belt.
  • Clean all your pulleys to make sure they are free from debris and rust.
  • Make sure that your spindle housings are in good
  • condition.
  • Check your idler tensioner bracket or spring to make sure it is not worn or broken.
  • Keep your mower belt lubricated with a high-quality belt lube.
  • Replace any parts on your Cub Cadet that may be worn or broken.
  • Follow the manufacturer’s instructions when installing your belt.


Cub Cadet deck belts can be pricey, but with proper maintenance and regular inspections for wear and tear, you can keep your belt running smoothly for a long time. If you do find yourself needing to replace the belt on your Cub Cadet mower, make sure that you follow all of the steps outlined in this article before you begin. With the right tools and knowledge, replacing your Cub Cadet deck belt can be a breeze.

Related Post 

brand new lawn mower won t start

Leave a Comment