One day while mowing with your zero-turn mower, you observed that it is not driving straight. This widespread problem has affected a significant number of zero-turn lawnmowers, so you are not alone. Now, you must wonder what causes the problem and how to solve it.
Some of the most common causes of the problem are unmatched tire pressure, unadjusted traction, dragging brake, imbalanced blade weight, bad dampers, etc.
This article describes in detail the causes and solutions for why a zero-turn mower pulls to one side rather than driving straight.
What Causes a Zero Turn Mower Pulls to One Side?
A list of the reasons why a zero-turn mower pulls to one side and their respective solutions are provided.
|Causes of Zero-turn Mower Pulls to One Side||Solutions|
|Unmatched Tires||Improper Tire Pressure||Equalize the tire pressures.|
|Unadjusted Traction||Adjust the traction.|
|Steering Problems||Unadjusted Drive Arms||Adjust drive arms.|
|Bad Dampers||Replace the bad dampers.|
|Brake Problem||Dragging Brake||Repair the dragging brake.|
|Hydrostatic Transmission Problems||Air in the Hydrostatic Motor||Refill with refined hydraulic fluid.|
|Displaced Freewheeling Rod||Repair the freewheeling rod.|
|Mower Deck Problems||Imbalance Blade Weight||Balance blade weight.|
|Stripped Spindle||Repair or replace the spindle.|
Most Common Causes and Solutions of Zero Turn Mower Pulls to One Side
Five categories represent the vast majority of factors that cause zero-turn mowers to pull to one side.
- Unmatched Tires
- Steering Problems
- Brake Problem
- Hydrostatic Transmission Problems
- Mower Deck Problems
1. Unmatched Tires
The category of unmatched tires includes the following causes:
· Improper Tire Pressure
Uneven tire pressure is one of the primary causes of your zero-turn mower’s pull to one side, preventing it from driving straight. One side of the mower may not engage as much as the other if the tire pressures are not equal.
The main reason for this is that the tires carry the entire load and aid in maneuverability. Therefore, low tire pressure renders the mower unstable and difficult to handle and it will cause the mower to pull to that side.
· Unadjusted Traction
When both throttles are pushed forward at the same time, but one wheel transfers more power than the other, then the zero-turn mower may experience traction problems.
Due to this, the mower may be weaker on one side, causing it to lean toward the weaker side. Also, unadjusted traction on one side stops the spinning of the blade.
Follow the troubleshooting steps to solve the improper tire pressure and unadjusted traction:
Step 1: Check Tire Pressures
- Start by parking the mower on a level surface.
- Using a tire pressure gauge, check the tire’s pressure by removing the cover.
Generally, the maximum PSI is written on the side of each tire. Compare the maximum PSI given on the tire with the measured PSI of your tire.
Step 2: Equalize Tires Pressure
- Fill the tire with air if the pressure is too low, and vice versa.
- Avoid exceeding the maximum PSI for each tire by using the same process for each.
- In addition, ensure that the tire pressures on both sides of your mower are similar.
Step 3: Adjustment of Traction
If tire pressures are not equal, adjust the traction of tires.
- Remove the rubber cover from the hub of the wheel with a pair of pliers.
- Then, remove the snap ring placed beneath the cap.
- Use the spare tire from the tractor on the mower.
2. Steering Problems
Steering problems include causes like unadjusted drive arms and bad dampers that causes the zero-turn mower to pull on one side.
· Unadjusted Drive Arms
If the mower’s steering isn’t properly aligned, you’ll lose control while mowing. Even while it’s not a serious issue, it nevertheless has the potential to push your mower in the wrong direction.
· Bad Dampers
The dampers prevent the ground from being torn to shreds and the hydraulic system from suddenly changing direction by absorbing excess pressure.
Usually, they spring to pull the control arms back to their neutral position. Therefore, when you are trying to speed up with a bad damper, your zero-turn mower might pull to one side.
To diagnose unadjusted drive arms and bad dampers, the following steps should follow:
Step 1: Adjust the Height and Width of the Drive Arms
- Unscrew the screws on the upper drive arm base handlebar hardware to remove it. Adjust the position of the handlebar as necessary. Then, reattach the hardware’s screws.
- Take the screws out of the base of the lower drive arm. Fix any hardware screws that may have come loose and tighten the eccentric spacer nut.
- Change the lever reach to move the lever back and forth.
Step 2: Adjust the Drive Arms Alignment
There are bolts in the bottom part of the driving seat. Adjust by tightening or loosening the bolts. Then, check whether the drive arms are aligned.
Step 3: Change Dampers
If the problem persists, then the simple solution is to replace the dampers.
The springs also could be changed out. This is because the new dampers don’t always cause the drive arms to be pulled back.
Read Also: What Size of Zero Turn Do I Need?
3. Brake Problem
The zero-turn mower’s brake may drag during mowing, causing the mower to pull to one side.
· Dragging Brake
If your riding mower is equipped with disc or drum brakes, one brake may not release as cleanly as the other, causing the mower to pull to one side.
Also, it may be due to a frozen brake caliper. It is possible for the piston to become tangled within the caliper. This may lead to misaligned and frozen brake pads.
Step 1: Repair the Dragging Brake
This issue can be fixed by removing each tire and repairing the brake.
For stuck caliper pistons or sliding pins, a straightforward C-clamp is utilized to apply pressure and retract the pad. A seized caliper piston can be released by the hydraulic force of the brake system.
4. Hydrostatic Transmission Problems
The following hydrostatic transmission-related problems also cause the zero-turn mower to pull on one side.
· Air in the Hydrostatic Motor
You may encounter cavitation of the hydraulic fluid used in the hydrostatic system. This can occur in just one of your mower’s hydrostatic motors, causing only one side to lose power.
· Displaced Freewheeling Rod
Freewheeling Rods are utilized in order to disengage the hydrostatic motors. A zero-turn mower may pull to one side due to a partially damaged, displaced freewheeling rod.
If the freewheeling rod of one of your mower’s hydrostatic motors becomes displaced, that motor will become weakened and one side will lose power. Therefore, the zero-turn mower pulls to one side.
Step 1: Refuel with Refined Hydraulic Fluid
- First, inspect the hydraulic fluid’s condition.
- If air has contaminated the fluid, drained the fluid by removing the drain cap.
- After that, the engine should be refueled properly.
- If the oil reservoir is empty, it should be refilled.
- Perform a test run to see whether it now functions correctly.
Step 2: Repair the Displaced Freewheeling Rod
To fix the problem, take a look at the freewheeling rod on the weak side of the mower and make sure they’re not damaged or out of position.
This problem can be resolved by repairing or replacing the damaged freewheeling rod. There are replacement parts available at any hardware store.
5. Mower Deck Problems
The mower deck problems that cause the zero-turn mower not to drive straight include the followings:
· Imbalance Blade Weight
Your zero-turn mower could drag on one side if one side of the blade is heavier than the other.
· Stripped Spindle
The spindle is a little piece of metal that connects the blade to the shaft of your mower. This is located on the pulley of your zero-turn mower. A stripped spindle can cause your blade to wiggle on one side.
Step 1: Balance the Blade Weight
- Spin the mower to determine blade weight balance. Balanced blades spin freely, but unbalanced blades spin unevenly.
- The problem can be solved by adding weight to the weaker blade until both are balanced.
Step 2: Repair or Replace the Spindle
The stripped spindle must be repaired in order to resolve the issue. If it cannot be repaired, then replace the spindle as instructed below:
- Remove the cover from the socket and the mower deck spindle assembly cover by loosening three bolts with the 1/2-inch wrench.
- Remove the belt from the mower deck using a 1/2-inch wrench.
- Use a socket wrench and cheater bar to loosen the tensioner pulley and lower the belt.
- Remove the nut from the top of the spindle using the 1-1/8-inch wrench and an adjustable wrench or socket.
- The stripped spindle should then be replaced with a new one.
Frequently Asked Questions (FAQs)
Is It Risky to Use Zero-Turn Mower with A Weak Side?
Yes, it is risky to operate a zero-turn mower that pulls on one side.
When you realize that your zero-turn mower leans to one side and is improperly balanced, you should repair it. The issue could lead to an accident if it is not resolved.
How Traction Difficulties Cause My Zero-turn Mower Pull to One Side?
One wheel of a zero-turn mower may transmit power more efficiently than the other, causing the mower to push toward the side with less traction.
How can I find out why one side of my zero-turn mower is weak?
Troubleshooting is the easiest approach to figure out why. Tire pressure, blade balance, and other potentially worn or faulty components should all be checked.
How can I Maintain a Zero-Turn Mower’s Straightness?
Apply equal forward pressure to both steering arms to keep the zero-turn mower straight and parallel.
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