5 Husqvarna Hydrostatic Drive Problems & Fixes!

husqvarna hydrostatic problems

The Husqvarna hydrostatic lawn tractor is a valuable household machine, especially during spring when the lawn grows rapidly. However, like all machines, this lawn tractor periodically develops issues that make mowing your lawn unnecessarily challenging. 

So what are the common Husqvarna Hydrostatic Drive Problems to look out for? The Husqvarna hydrostatic lawn tractor may not power on, start smoking, be unable to reverse or move forward, experience transmission failure, or become unsteerable. 

These problems can be particularly frustrating if you don’t know why they’re happening or how to solve them. Not to worry, we will explain these problems and how you can resolve them in detail. 

5 Common Husqvarna Hydrostatic Drive Problems

Husqvarna Hydrostatic Lawn Tractor Won’t Power On

There are several reasons why your Husqvarna lawn mower may fail to start. Let’s discuss three reasons why your lawnmower may fail to start.

● Defective spark plug 

Another reason your Husqvarna Hydrostatic machine won’t power on might be because of a faulty spark plug. Your machine’s spark plug ignites the fuel combustion that starts the engine, and when the plug is clogged by carbon —the dark substance that appears at the tip— the spark plug becomes unable to ignite

Fix: Take out the spark plug and examine it for carbon build-up. Then, clean the terminal with sandpaper or a wire brush. If this does not rectify the problem, it will be best to change the plug.

● Bad or old fuel

It’s pretty common for gas to degrade 30 days after buying it. The product of this gas deterioration is a sticky residue that clogs the fuel system, including the fuel filter, carburetor, and fuel line.

Fix: Luckily, fixing this issue is quite simple. Drain the old fuel in the lawn tractor’s tank and fill it with new fuel. 

● Clogged carburetor 

A carburetor controls the amount of air fuel that combusts in the cylinder. However, fuel additives, like ethanol, leave behind sticky substances that clog the machine’s carburetor and restrict the quantity of fuel entering the engine. 

Fix: The best fix is to clean the carburetor or replace it (if the damage is unsalvageable). We recommend visiting a skilled technician for this fix. Nevertheless, if you have experience fixing lawn tractors, you can do it. 

Tip: Ensure you use the fuel in your Husqvarna’s engine within 30 days to prevent the gas from degrading and clogging essential components on your machine. 

Husqvarna Hydrostatic Lawn Tractor is Smoking

Noticing smoke from your machine is a worrying sight —Don’t worry; we know how it feels. If your lawn tractor is smoking, here are possible causes.    

● Damaged head gasket

A faulty head gasket can cause smoke from your lawn tractor. A damaged head gasket will cause oil and coolant to seep into the machine’s combustion chamber.

Fix: You need to replace the damaged head gasket to stop your machine from smoking.  

● Dirty air filter

The Husqvarna’s air filter protects the engine from debris. However, as time passes, the air filter may get clogged. This blockage will cause the engine to smoke because it’s not receiving adequate air supply. 

Fix: Replacing the air filter is the quickest and most effective way to solve this issue. If your lawn tractor’s air filter is made of foam, you could wash it with soap and water instead. 

Husqvarna Hydrostatic Lawn Tractor isn’t Reversing or Moving Forward

Many users report being unable to move or reverse their Husqvarna mower. Let’s find out why this happens. 

● Faulty tensioner pulley 

The tensioner pulley tightens the belt of the mower’s pulley system. If this part fails, the entire pulley system may not work correctly. 

Fix: Replace the faulty tensioner pulley in the machine.

● Worn-out drive belt 

The drive belt is responsible for driving a system of pulleys that makes the machine move. The engine and clutch power the drive belt, and when it becomes defective, your mower will have issues moving in any direction. 

Fix: Replace the worn belt. Also, check that the belt is securely wrapped around the machine’s pulleys.

● Low or old hydraulic oil

If the hydraulic oil in your lawn tractor is old or too little, the hydraulic system won’t lubricate sufficiently. This insufficient lubrication will cause the machine to operate slowly; in some cases, the machine may fail to move. 

Fix: Change or top up the hydraulic oil in the engine.

Husqvarna Hydrostatic Lawn Tractor Transmission Failure

Your lawn tractor may encounter issues with its hydrostatic transmission system. This issue will lead to difficulty when shifting your lawn tractor and hamper its performance. 

● Faulty drive belt 

A faulty drive belt can cause your machine’s pump to perform inefficiently. We recommend checking the drive belt on your lawn tractor at regular intervals to verify that it is in working condition.      

Fix: Simply replace the faulty drive belt

● Defective tensioner pulley      

If the tensioner pulley on your machine is defective, it becomes unable to keep tension on the tractor’s drive belt, leading to transmission issues. 

Fix: Replace the tensioner pulley and lubricate the arm.

● Low or old fuel or hydraulic oil      

Low fuel or hydraulic oil in your lawn tractor will cause your hydraulic system to function poorly, causing weak transmission.   

Fix: The fix for this issue is straightforward. First, make sure your machine’s fuel and hydraulic oil are at the right levels, then top up as required. We also recommend changing your fuel or hydraulic oil at regular intervals. It seems easy, right? 

Fun fact: Hydrostatic transmissions use hydraulic fluid to shift gears automatically. This is the most common type of transmission found on lawn tractors and is more efficient than other transmission types.

Husqvarna Hydrostatic Mower Steering Out-of-control

You can’t get that perfect stripe of grass if your machine moves haphazardly. So, if your Husqvarna lawn tractor can’t steer straight, it virtually makes the machine unusable. This problem may be down to a few reasons; let’s discuss a few.

● Unbalanced tire pressure

When the tire pressure is not balanced, you may notice your machine veering uncontrollably. Remember that you must follow Husqvarna’s recommended tire pressure specifications for the best results.

Fix: Check the tire pressure of the Husqvarna mower and fill the affected tires appropriately. Remember, all the tires on your mower require equal pressure.

● Faulty steering dampers

Dampers stabilize the lawn mower when mowing on uneven terrain. If the dampers on your machine are bad, the lawn tractor may steer in the wrong direction.   

Fix: Replace the faulty dampers with new ones.

● Worn-out steering components       

Worn bushings, washers, and gears are another reason the Husqvarna may steer out of control. All these components work to balance the machine, so when they become defective, your mower will not steer properly. 

Fix: All you have to do is inspect and replace any defective steering components.

Frequently Asked Questions

How do I set the hydrostatic drive on my Husqvarna lawn tractor?

Push the throttle forward for about five seconds. Then, pull the throttle into reverse and hold for five more seconds. Ensure you repeat this step three times for effective results.

How do you troubleshoot a hydrostatic transmission?

First, check the machine’s oil level, the inline pressure filters, and the relief valves. Then, look at the heat exchanger, pump, and motor case drains for extreme bypassing.

What other Husqvarna hydrostatic drive problems should I look out for? 

Your lawn tractor may leak gas when you’re mowing. If you notice this problem, check the carburetor, fuel filter, fuel pump, and fuel tank. If you see any damage on these parts, we suggest you replace them. Additionally, your tractor may vibrate during use. This issue may be due to a faulty clutch, loose bolts in the engine or debris stuck underneath the mower.


As you can see, all these problems have solutions. If your machine is experiencing any of these, get your toolbox and start fixing it!

However, if you’re unfamiliar with how the internal systems of this machine work, you should consult an experienced repairer. Don’t worry; most of these replacement parts are inexpensive, so you won’t have to spend a fortune before you can continue trimming your lawn.