From time to time, your ATV does not behave the way you want it to. One of the most common issues you may experience is that your bike suddenly or gradually starts pulling or drifting to the left or right.
If you are lucky, there may be an easy explanation for your problem.
The most common reason why an ATV pulls either to the left or right is a difference in the front wheels’ circumference due to different air pressure.
Wear or damage to the various components in the undercarriage of the quad can also result in these kinds of issues.
If adjusting the tire pressure or replacing worn parts doesn’t resolve the issue, the front wheel alignment may be out of order and needs to be addressed.
Let’s take a closer look at some of the most common reasons an ATV pulls to either side and how to fix them.
Troubleshooting an ATV That Pulls to the Left or Right
You need to do some troubleshooting to find the actual reason why your ATV is wandering off into the ditch when you want to go straight.
As with all troubleshooting, I recommend you begin with the most likely and easiest-to-check issue before spending time and money on more uncommon and potentially more complex solutions.
1. Check for a Difference in Wheel Circumference
In my experience, the most common reason, and definitely the most straightforward issue to check and fix, is the different circumferences of the front wheels on either side.
Basically, this means that each time the wheels turn, one wheel drives a slightly longer or shorter distance than the other. This will most certainly make your bike pull to the side, which has the smallest circumference wheel.
But the wheels are identical and have been in use for the same amount of time and mileage. How can this even be an issue, you might ask.
The Most Likely Cause: Different Tire Pressure in the Front Tires
ATV tires are relatively soft and flexible, so they basically act like balloons when you put air into them. Although not as visible as on the birthday type, they still expand quite a bit when inflated with more air.
More air equals a bigger tire with a larger circumference. If the ATV pulls to the right, the front right tire pressure might be too low. The same applies to the left tire if it pulls to the left.
What you need to do, is to make sure both tires are set with the correct factory-specific tire pressure or to your personal preference for the intended use. Use a good tire pressure gauge to check your levels.
Most ATV brands come with one in the tool kit. If you can’t find it I strongly recommend getting one as soon as possible; they are not expensive. Just a two to three pounds difference between the tires can be enough to create an issue.
You should check both the front and rear tires.
Although uneven pressure in the rear tires is less likely to cause your pulling issue, it’s worth controlling them when you are at it. It’s not good if they don’t have the same circumstance, as that will cause them to “fight” each other and may cause premature rear diff wear.
Caution! Never exceed the maximum tire pressure, usually written on the side of the tire.
Please refer to your user manual if you are unsure what pressure is safe or optimal for your machine.
Note that the front and rear tires might have different pressure ratings. What is important in this case is that both front tires have identical pressure, and also, both rear tires read the same levels.
Now you can find a tape measure or a piece of string to measure the circumference—Jack up the quad for proper access.
If you use the string, you just put a mark when you measure one side, and then the other side should be identical. If they are the same, you are good to go!
Here is another easy method you can try to check if the circumference is the same:
- Place your ATV on level, smooth ground, and mark each front tire’s sidewall with a piece of chalk at the very bottom.
- The wheels should be pointing straight forward, and the ATV should be in neutral.
- Then push the bike forward until the tire has made two or three full turns, and the mark you just made on the tire is back at the bottom where it started. Pay attention to only one of the tires when doing this.
- Then have a look at the mark on the opposite tire. Ideally, this should also still be at the very bottom. If this is not the case, the circumference is not the same as on the other tire.
- If the ATV pulls to the right, the right tire likely has a smaller circumference.
- If the ATV pulls to the left, the left tire is likely smaller.
When the Tire Circumference is Uneven With the Correct Tire Pressure
It’s important to know that even if both tires have the same pressure, the circumference is not necessarily the same.
While this is generally more true for bias-ply tires than radials, the tire dimension will sometimes be altered over time simply because of treating them differently.
If you, at some point, have put more tire pressure in one of the tires than you usually use, this may have stretched the tire and altered the circumference by as much as a couple of inches. This may happen even without exceeding the maximum tire pressure.
You can try to correct this by putting about 90% of the maximum tire pressure in both tires and leaving them for a few days. I don’t see the need to go all the way up to maximum pressure, as 10% below maximum is still far over normal riding pressure and should have the same effect.
Doing this procedure may stretch the tires evenly. Then you should adjust the pressure back down to your preferred riding pressure and recheck the circumference.
If this does not make the tires the same size with identical tire pressure, you can inflate the smallest tire slightly more than the other until the circumference is the same. Then, the next time you buy new tires, you remember to never put more air in one of them than the other!
But remember, and this can not be said too often: Never exceed the maximum rated tire pressure as an exploding tire may be fatal, even with lower pressure levels like ATV tires usually should have.
2. Check for Wear in Tie Rod Ends, Ball Joints, Bushings, & Bearings
For this step, you must start by jacking up your quad so that all four wheels are off the ground simultaneously. You can do this in many ways; just make sure the bike is stable.
I recommend that you find a hard-level surface like a concrete floor and use a good-quality jack. I like placing a couple of wooden blocks under a flat spot in the center of the quad, one in front and one in back.
If you like maintaining your ATV yourself and have to lift it quite often, it may be well-spent money to get a purpose-made ATV/motorcycle jack. But it is not mandatory for this inspection.
You want to ensure you don’t have free play in the tie rods or A-arms. Just grab them and feel for play by pulling them in different directions. Play may occur due to wear over time or bolts coming undone/loose.
Then see if all the bushings are securely fastened and not loose or worn in any way. The steering column bushing usually wears over time. The same goes for the ball joints on the tie-end rods.
Tighten any loose bolts or replace worn parts. Worn components can soon break, so replacing them is never a waste, even if they are not why your ATV pulls to the side.
But remember that an ATV’s undercarriage is not entirely free of play even when the machine is brand new. Some small play may be perfectly normal and doesn’t necessarily mean you have to replace any parts.
You should also check for any wear in the wheel bearings or the bearings in the axle carrier.
For the wheels, place on hand on top of the tire and the bottom, and then try to wobble it back and forth to see if there is any play.
Grab the axle on both sides and check for play in the carrier. Again I must mention that even on a brand-new bike, I have experienced some play when doing this test, so you shouldn’t expect it to be 100% tight.
Finish this point by greasing your undercarriage if your ATV has this option.
Your user’s manual will give good instructions on what components should be addressed with the grease press. Usually, bushings and bearings, although some machines have sealed bearings that do not require service.
This often neglected maintenance is cheap and will greatly prolong your components’ life and prevent water from entering with rust development as a result.
3. Check for a Bent or Damaged Undercarriage
Visually inspect the undercarriage components to identify bent or damaged parts.
The A-arms are especially prone to bending if you hit a stump or a rock while going off-road. The «fast-growing» trees that seem to pop up suddenly just in front of the ATV when you ride are the worst!
The A-arms are actually designed to be the part that breaks first to avoid damaging components that are harder or impossible to repair, like the ATV frame. But it is not always easy to see whether they are bent. Some even come with a curve from the factory.
My best tip is to try to find an angle to compare them to the tie rods.
The arm is likely bent if they are parallel on one side but not on the other. This method is much easier on a snowmobile, where you can stand at your machine and aim down on both A-arms to compare.
Also, check the shocks for any visual damage.
If the ATV was tipped over, the steering column and/or tie rods could be damaged. If the bolts on your steering column contact nearby components at a full turn, it is likely bent. Steering hoops may also be bent, depending on how bad the rollover was.
4. Check the Diffs and Brakes
While your ATV is still jacked up, you may as well check if your diffs are healthy. If they are damaged, the power distribution might be off, sending all the power to one of the wheels, naturally causing a pull to one side.
It’s easy to test this. With the 4×4 engaged and the ATV in gear, try spinning one of the front wheels; if the other wheel spins freely in the opposite direction, then your diff is likely okay. Also, try this with the 4×4 disengaged.
Then put the bike in neutral and check that all four wheels spin freely with no brake drag or grinding sounds. If the brake is dragging on either side, you should address this.
5. Ensure the Toe Alignment Is Correct
The reason why I didn’t address misalignment before in this step is quite simple. I don’t want you to fall for the temptation to start adjusting the bike before you are sure that none of the above reasons cause your troubles.
Even tho making adjustments may improve the situation, even if your problem is one of the above, you are not addressing the real issue; you are just compensating without fixing what is really making your machine pull to the side.
Your rear tires should generally always be parallel to each other and perpendicular to the ground. The front tires, on the other hand, should be leaning slightly toward the ATV. This is called camber.
Depending on your intended use, they should also be angled slightly inward (toe-in) or outward (toe-out). Some riders even prefer parallel front tires.
On stock ATV suspension, you usually don’t have the option to adjust the caster and camber as you may have on a car. These are set at the factory and should normally not be an issue. This basically leaves just the ability to adjust the toe-in on your bike.
Most manufacturers advise against owners making this kind of adjustment at home. So in this article, I will not address the alignment procedure.
But what you definitely can and should do, is control if the toe alignment is set according to factory specifications.
Your user manual usually has brand-specific instructions and recommended toe-in specs. The recommended specs vary depending on the intended use of the machine.
For sport and recreational riding applications, it is recommended to have a slight toe-in.
This means that the distance between the rims’ front is slightly shorter than at the back, usually no more than 6-12mm. This gives a more precise and responsive steering response.
In racing, it is common to prefer a parallel adjustment of the front wheels to reduce drag and increase performance.
For utility ATVs, on the other hand, it is recommended with a slight toe-out. This means that the distance between the rims’ front is slightly longer than at the back, usually no more than 6-12mm.
This setup makes the bike more stable, especially when carrying heavy cargo on the front rack.
Many riders use their utility ATVs mostly for trail riding and prefer a slight toe-in for better handling.
This Is How You Check the Tire Alignment on Any ATV
- Place your ATV on a hard, level surface like a garage floor.
- Place the handlebars as if going straight ahead. Visual alignment is usually accurate enough. Optional, but important if you make any adjustments yourself: Fasten each side of the handlebar to a fixed location at the back of the bike using tie-down straps to ensure it doesn’t move out of position.
- Tie a string between two stands and place the stands on one side of the ATV so that the string is parallel with and barely touches the rear tire.
- Then measure the distance between the string and your rim at both the front and back of your front wheel. The difference between these two measurements should be the same on both sides of your ATV and according to factory recommendations.
If you don’t have a string and stand available, or if you want more accuracy, use this method:
- Measure the distance from the ground to the wheel’s center to find half the tire’s height.
- Use this measurement to mark off four measuring points on the inside of the wheels. You’ll need one mar in front of the axle and one behind the axle, both at the same distance from the ground. For the best accuracy, I prefer placing the marks on the rim, not the tire.
- Then measure the distance between the two front marks and then the rear marks. Compare the measurements against your desired specifications.
6. Avoid Low-Quality Tires
If you still have stock tires on your quad, they are not always the best quality. They may seem perfectly fine, but manufacturers often choose cheap tires to keep the bike’s price as low as possible.
Also, they know that changing to better tires is often one of the first upgrades people do to their ATVs, so there is no need to break the budget on tires that will be replaced anyway.
Upgrading to a decent aftermarket tire may vastly improve your machine’s riding performance and may also eliminate any issues you have with pulling to the side.
Until recent years, almost all ATV tires were bias-ply tires. Remember that this tire style is not ideal for pavement use. They generally get warmer when you ride and are less resistant to wear.
Any abnormal or uneven tire wear will most likely affect the ability to go in a straight line on a paved road. If you ride mainly on hard, smooth surfaces, you may want to consider investing in some radial tires instead.
When buying new tires, you can test them when they are brand new with the method in checkpoint one.
If they don’t have close to identical circumferences when tire pressure is the same, I would take them back to the dealer and ask for a new set or consider a different make and model.