A Zero-turn riding mower should drive smoothly and effortlessly. Now that the mower can no longer do it, it has something to do with poor traction. However, there are other causes. Your zero-turn mower pulls to one side due to unbalanced blades, incorrect tire pressure, faulty dampers, or malfunctioning drum brakes.
If your lawn mower faces this issue, you are in the right place. In this blog, we will discuss the causes of this irritating problem. Moreover, we will provide insight into its suitable fixes.
Why does your Zero-turn Mower Pull to One Side?
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A ZT mower is different from other lawn-mowing equipment. It relies on 2 different drive systems on each side. With one of these systems failing, the machine will pull to the non-failing side.
Aside from this obvious scenario, you can misplace some attachments, such as small trailers, in a way that makes the mower drag on one side.
1. Uneven Tire PressureÂ
Incorrect pressure is one of the apparent reasons why a lawnmower pulls to one side. This issue makes driving straight a challenge. Improper pressure makes both back wheels unequally engaged.
Generally, the tires on all tractors and mowers carry the weight and facilitate maneuverability. If one of the tires has more pressure than the other, the former will carry more load. Subsequently, the vehicle will lean toward the fuller tire.
2. Poor TractionÂ
The mower will sink in the grass or stall during cutting without proper traction. Correct traction also spares your lawn a lot of damage. Throttle adjustment controls power transfer to the wheels.
If you push these controls forward, one of the two driving wheels in the back will receive more power. This scenario results in dragging the machine toward the less powerful wheel.
3. Faulty DampersÂ
A functional steering damper works as a shock absorber. It eliminates accidental turf tearing while mowing on rough terrain. Moreover, it reduces jerky movements around obstacles. Once this component malfunctions, your garden tractor will lose its balance and stability.
You will notice a sudden instability in the motion of the mower deck, especially when handling uneven terrain. So, if you want the best performance from the mowing deck, you should take good care of the dampers.
4. Poorly Adjusted Steering ArmÂ
Unadjusted drive arms are the most common problem in the steering system. This trouble is not the worst or the most severe issue; however, it will affect your ability to control the zero-turn lawn mower direction.
5. Malfunctioning SpindlesÂ
The spindles are an integral part of the cutting deck of all ZT mower models. This component mainly rotates the blades, leading to smooth operation and efficient grass-cutting. Also, the spindles contribute to turning the wheels.
Any signs of malfunctioning in this component will reflect on the steering control and ability to drive straight.
6. Bad Drum BrakesÂ
This problem occurs when the brake system drags to one side. Mowers with drums or disc brakes tend to have this problem, as one does not respond as fast as the other. Drum brakes are only found on the back wheels. So, your mower has a set of two brakes.
 7. A Problematic Hydrostatic SystemÂ
Any problem in the hydrostatic units will directly affect the balance and steering of your tractor. One of this system’s most vital and visible issues is decreased hydraulic fluid. Also, the quality of hydro fluid may need improvement. It might be dirty and will eventually clog important system components such as the hydraulic pump.
Another relevant issue is the freewheel rod that is located on each wheel. It might be worn or damaged, which causes the mower to pull to one side.
8. Unbalanced BladesÂ
The mower’s blades cut off dead and uneven grass. The blades will do the job excellently if everything is alright in the deck. However, if you start to experience vibration from the deck, this indicates either damage or unbalanced blades. Additionally, a mower that has defective blades would be challenging to maneuver.
How to Fix a Zero-turn Mower that Pulls to One Side?
Knowing all the causes of your machine pulling to one side can guide you to the proper fix. Fixing a drive belt or correcting steering adjustments is a hassle for some users. However, addressing these issues will save you further maintenance costs and even purchasing a new mower.
1. Make the Tire Pressure EqualÂ
Diagnosing uneven pressure is easy with the naked eye. However, you can use a pressure gauge to make a more accurate measurement. Then, fill the lower tire adequately. Look at the tire’s side for reference on the max PSI. Make sure to perform this procedure on even ground for optimum results.
2. Increase TractionÂ
Increasing a mower’s traction is a broad concept that combines various aspects. First, you can choose larger tires and adequately reduce their pressure. Then it would be best if you changed your mowing style.
For instance, you should avoid working on wet or inclined lawns. Lastly, if you have to mow on a hill, ensure the mower’s nose is directed uphill. This contributes to reducing the pressure on the front wheels.
3. Change the DamperÂ
It would help to immediately inspect the deck once your mower drags to one side. You need to ensure the condition of the dampers. The dampers need to be replaced if there are any symptoms of wear and tear.
In some cases, the damper springs get equally damaged. So, it is better to change the two components together. Taking this precaution will prevent the dampers’ failure to push against the control arm.
4. Readjust the Drive ArmsÂ
You can diagnose malfunctioning drive arms by persistent steering difficulty. If you inspect the arms, you will find them improperly aligned and have to work on this. You can do this by manipulating the steering adjustment bolts. These bolts are located right under the seat.
You can use your socket wrench to loosen or tighten the bolts accordingly. Stop the work once the arms are correctly aligned.
5. Change the Spindles
Being attached to the deck makes this component prone to constant wear and tear. So, it is no wonder you find the spindles broken or damaged more often. This part is easy to replace if you have the essential experience in removing and reinstalling the blades and the deck’s pulleys.Â
Otherwise, you should consult with a certified technician.
6. Fix the Brakes
As you already know, the drum brakes are part of the back wheels. So typically, you will have to remove the tires to access them. Then you should clean the brake assembly and maintain the position of the brake shoes.
Keep in mind that improper handling of the shoes might release loads of dirt into the air. It is preferable to speak with a professional if you are unsure of your abilities to maintain these brakes.
While at it, ensure there is no frozen brake caliper. This problem may result from stuck pistons. So, it is worth checking out.
7. Fix the Hydrostatic TransmissionÂ
Refilling fluid levels with the user manual is the key to overcoming most hydro issues. Make sure that the oil reservoir is filled with clean fluid. As for a malfunctioning rod, you may have it replaced by an expert to avoid misplacement issues.
8. Balance the BladesÂ
To properly diagnose this issue, you will need this simple test. Shut off the engine, turn the mover over, and spin the blades manually. Imbalanced blades will not spin equally. You will need to remove the blades and ensure they are sharp. Then you can get a balancer to make both blades evenly balanced.
Marvin is an expert in farming equipment with a strong background in agricultural engineering. He graduated from Kansas State College of Agriculture, where he received a degree in Agricultural Engineering and specialized in farm equipment design and maintenance.
