How to Fix an ATV Belt Slipping
There are many reasons you could experience CVT belt slippage. It's helpful to know how to prevent and how to fix ATV belt slipping so you do more enjoying of your machine and less fixing.
Common Symptoms of a Bad CVT Belt
The primary problem you'll experience with CVT belt problems is loss of performance. Depending on what's wrong with the belt, you might feel a jerking sensation at takeoff, smell burnt rubber, see smoke, or notice that the clutch will only engage at higher rpms than normal.
The Most Common Causes of CVT Belt Problems
The belt is wet
Water is a very common cause of ATV belt issues. The belt gets wet and reduces the friction between the belt and the clutch sheaves and simply can't work until it dries.
When this happens, you can drain water out of the housing by pulling a drain plug at the bottom of the housing. Give the casing and/or belt time to dry and then further dry it by idling the machine in neutral to cause some friction. It should take a matter of minutes to be ready to ride again. When you do, start slow to prevent slippage.
If this is a recurring problem, you can make it much less likely to happen again by:
- replacing worn or badly seated seals in the casing
- checking the casing for damage and repairing it
- riding at lower speeds in water, mud, and snow
- installing a snorkel if you frequently ride in water and wet terrain
The belt has overcome serviceable limits
The friction that makes the belt work also wears it down over time. This can be exacerbated by excessive heat and your riding style.
Routinely check the belt for cracks, missing chunks, and reduced thickness. If the belt gets too thin, it can't rub against the sheaves the way it should anymore. Your owners' manual will tell you the exact measurement you need on your belt.
Replace the belt when it is cracked, missing chunks, or thinner than the minimum thickness.
The belt doesn't fit your ATV model
Belts are not one-size-fits-all. You will likely have this problem after installing a new belt. Make sure any belt you buy fits your specific ATV model, even if that means you have to buy an OEM belt. If you are determined to use a certain size belt, you can adjust the clutch sheaves to compensate.
The belt isn't broken in properly
Many new ATV owners don't know this, but you need to give any new belt, on a new ATV or when you install a new belt, time to break in before you hammer the throttle. Not properly breaking in a belt causes belt burn and slippage.
When you install a new belt, clean it with soapy water to remove grease and oils and then let it dry completely before installing it.
On a new ATV or when installing a belt, bring the machine up to normal operating temperature by running the machine in all the shifts, making sure to never exceed 3/4 throttle. Do this for about 15 minutes.
Turn off the machine and let the belt cool. It should take around 30 minutes for it cool completely.
Go through this process two or three more times and then you will be ready to ride normally.
The belt is burned
It is fairly easy to burn a CVT belt. As mentioned above, you can burn it by riding it at full throttle without breaking it in first. You can also burn the belt by riding your machine hard and not cooling it before turning it off.
If you've just put a lot of strain on your machine, run it in neutral and rev the engine for a few seconds to cool down the clutches before you turn it off.
You've installed bigger tires without upgrading the clutches
It isn't intuitive, so many people don't realize that upgrading their tires makes the clutches less efficient, generating more heat, and damaging the belt. You can fix this by upgrading your clutch when you upgrade tires more than an inch larger.
You use high gear when riding hard in the mud
If you tow, climb hills, or tackle snow or deep mud in high gear, the clutches don't have enough time to shift completely and cause excessive heat that can burn your belt.
You can fix this by riding in a lower gear in these situations.
The clutches are not aligned properly
The drive and drive pulley need to be aligned correctly to prevent belt slippage and loss of performance.
You can fix this by checking your owners' manual for the specific alignment and purchasing an alignment tool for your ATV model.
The CVT system is clogged with mud or debris
If mud, sand, or debris get in your belt casing, it can interfere with the operation of your clutches.
You can fix this by removing the cover and belt and cleaning it with engine degreaser and a pressure washer. You'll want it to be completely dry before you reinstall the belt and close the cover. For nastier messes, you may need to clean the clutches too. Before you reassemble it, you'll need to add grease to the bushings and oil to the rollers.
You can do this repair yourself or have a dealer do it for you.
The clutch sheaves are damaged
If the clutch sheaves are damaged, they can ruin the belt. Remove the belt and inspect the sheaves for issues. If you find any, you can replace some of the sheaves or the clutches.
The rollers, helix, or clutch bushings are worn
If the rollers in the primary clutch are worn, they can cause slippage or inhibit movement. The helix and the clutch bushings in the secondary clutch can also be damaged and lead to wear. It is possible for a damaged helix and bushings to cause the clutch to explode and make the ATV completely inoperable.
This requires you to take apart the casing, visually inspect the parts for wear and damage, and check out your ATV's service manual.
The clutch bearing is worn
A bearing in the belt's pulley system can wear and make the pulley unable to release the belt. You can grip the clutch firmly and push it to check for slack. If you feel slack, you need to replace the pulley.