Your lawn mower just quit moving and you’re not sure why. Sometimes it’s an easy fix, but it can also be more difficult and increasingly more expensive when the problem is in the transmission.
A Husqvarna lawn mower won’t move or go forward when the drive belt is worn; the hydraulic fluid is low, old, or hot; the air is trapped in the hydraulic system; the axle key is missing in a lawn tractor, or the tensioner pulley and spring are broke on a zero turn.
Before working on your Husqvarna, shut off the mower and remove the spark plug wire. Take caution when working around a hot transmission.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
9 Reasons a Husqvarna Mower Won’t Move or Go Forward
Manual Transmission Bypass Lever is Not in the Operating Position
Husqvarna hydrostatic lawn mowers use fluid in the transmission. It pumps this fluid to turn the wheels. The lawn mower will have a transmission bypass lever that will allow the operator to manually push the mower.
When the lever or bypass is engaged to manually move the mower, you must disengage the bypass once you are done moving it so your hydrostatic transmission can properly move the wheels. If you don’t engage the transmission, your Husqvarna won’t move.
- Husqvarna zero turn: You will find two levers at the rear of your zero-turn mower, one for each transmission. (left and right).
- Husqvarna lawn tractor: You will find one bypass lever located at the rear of the tractor. You may find it near the drawbar or under the seat.
Belt is Worn, Loose, or Broken
Zero Turn Pump Drive Belt
Check the drive belt to make sure it sits securely on the pulleys and hasn’t fallen off. If your belt is worn it may slip on the pulleys causing your mower to move slowly. If it has fallen off the pulleys, it will not move.
Inspect the belt for wearing and replace it with a new belt if it isn’t in good condition. Reinstall a belt that has fallen off or broken.
Lawn Tractor Motion Drive Belt
Make sure the drive belt is not worn and is correctly routed around the pulleys. Replace a worn or damaged belt. The belt needs to be sitting securely around the pulleys and inside the belt guards.
If you find that a belt has fallen off the pulley, make sure the pulleys are in good condition and the belt guards are not bent or out of place.
Missing Axle Key in a Lawn Tractor
If you have recently changed your tire on your riding lawn tractor, you may have missed a small key that fell out of the axle. This key looks like a small narrow bar. It must be installed in order for the wheel to move.
Bad Husqvarna Mower Tensioner Pulley on a Zero Turn
Tensioner Pulleys are often made from hard plastic with a bearing in the center. The pulley can break or the bearing can fail on a Husqvarna lawn mower. If you find a bad pulley, replace it with a new one. Make sure the belt is securely around the pulleys and inside the belt keepers.
Worn or Missing Idler Arm Spring on a Zero Turn
The purpose of the idler spring is to place tension on the drive belt. Replace the spring if it is broken, missing, or stretched. Keep the tensioner arm greased on so it has some movement and doesn’t seize up.
Low Hydraulic Fluid Level or Old Hydraulic Oil
It’s important to keep your transmission system performing at its best by regularly checking and servicing the transmission as required. Some transmission systems found in Husqvarna riding mowers are sealed and unserviceable.
This means you cannot change the hydraulic oil. Refer to your operator’s manual to find out whether or not you are required to perform regular service on your transmission.
If your Husqvarna mower has a serviceable transmission, consistent hydraulic oil changes at intervals recommended by Husqvarna must be completed.
Keep in mind, the first hydraulic oil change is performed at a sooner interval than the others. Running your mower with old or low hydraulic oil can cause your lawn mower not to move or seem very weak while running.
When your hydraulic oil is low, add more hydro oil until the fluid level reaches the full level when your hydraulic oil is cool. It’s also a good idea to check for hydraulic fluid leaks to make sure your fluid level isn’t low due to a leak.
Hot Hydraulic Fluid
When you operate your Husqvarna lawn mower with bad hydraulic fluid or low fluid, the oil is not able to efficiently lubricate the hydraulic system causing increased friction and overheating of the hydraulic fluid.
Hot hydraulic fluid can also be the result of more extensive damage. I highly recommend taking the lawn mower to your local Husqvarna dealership if you experience leaking.
If your lawn mower runs fine when it is cold but stops running when it gets hot, you should have an experienced mechanic check your transmission.
Air in the Hydraulic System
After changing the hydraulic fluid on serviceable transmissions, you must bleed all of the air out of the system. Trapped air in the transmission can make your lawn mower move slowly.
Remove air in a Husqvarna zero-turn transmission
- Place on a flat surface. Secure the front wheels using wheel chocks to prevent the mower from rolling forward.
- Raise the rear drive tires off of the ground using jack stands and allow them to spin forward and backward until you don’t hear excessive noise and the wheels move at normal speeds.
- Open your bypass valve using the drive release levers located at the rear of your zero-turn.
- Start your mower, increase the throttle at a fast idle, and release the parking brake.
- Move the drive levers forward and then reverse 6 times to remove air from the system.
- Shut off your mower and set the parking brake
- Close the bypass valve and repeat the process.
- Start your mower, release the parking brake, and move the drive levers forward and reverse. Keep doing this until your transmission no longer makes excessive noise and the wheels move at normal speeds in forward and reverse.
- Refer to your operator’s manual for detailed steps to remove air from your model’s hydraulic system.
Remove air in a Husqvarna lawn tractor transmission
- Place on a flat surface in an open area.
- Turn the engine off and set the parking brake.
- Disengage the transmission using the lever at the rear of the tractor so the tractor freerolls.
- Sit on the tractor and start it.
- Place the throttle in the slow position and release the parking brake
- Depress the drive pedal to the forward position for about 5 seconds and then move to the rear position for 5 seconds. Repeat several times.
- Shut off the tractor and set the parking brake.
- Engage the transmission using the lever at the rear of the tractor.
- Get back on your tractor and do the same procedure as before, but this time with the transmission engaged.
- Make sure you have enough area to move the tractor forward and backward 10 feet in front of you and behind you.
- Start the tractor, and place the throttle about halfway.
- Drive your tractor forward for 10 feet and backward for 10 feet. Repeat several times.
Non-Transmission Related Items that Can Keep Your Mower from Moving
If you don’t find the fault of your moving problem due to a transmission problem, you can check these items that can prevent the fuel and air required to run your engine. Definitely check out these items if your engine starts to sputter or shuts off so you are no longer able to drive.
- Battery and Charging System
- Plugged Fuel Filter and Fuel Lines
- Plugged Air Filter
- Dirty Carburetor
Read more about items that can result in your mower stopping while mowing and how to fix them in “Reason Your Husqvarna Lawn Mower Starts Then Dies”.
Still Having Problems with Your Husqvarna Lawn Mower?
If you are still having problems with your mower, check out my guide on common problems owners encounter with their lawn mowers.
I put together a chart to identify causes and solutions to problems including starting, smoking, cutting, vibrating, dying, and more.
You can find this guide at Common Husqvarna Lawn Mower Problems & Solutions.
If you don’t feel comfortable troubleshooting and performing repairs on your lawn mower, it’s best to contact your local Husqvarna dealership or lawn mower repair shop for assistance.
You must remain safe and only perform repairs you are mechanically able to perform to avoid injury or further damage to the mower.