Husqvarna riding mower reverse problems

Whether you have just noticed that your tractor has developed a problem when reversing or if it was slowly building up with time, I’ll try to walk you through some troubleshooting and possible fixes of the issue in this article.

Do Husqvarna mowers cut in reverse?

You might find yourself in a situation where you attempt a backing-up maneuver with mower blades engaged, and your tractor just shuts off all of a sudden. That is just a sign that your RIO safety system is working correctly.

RIO or reverse implement option is a safety system built into your tractor that insures riders’ attention when backing up with an engaged mower deck.

It’s extremely important for the rider to be as attentive and alert as possible when backing up the tractor with engaged PTO  to insure the safety of little kids or animals that could be around.

Backing up is a more dangerous maneuver as the visibility to the back is limited due to the rider’s position and since the mower deck is placed closer to the back axle and tractor sides: the blind spot of the rider, it poses an additional danger.

An RIO system is made up of an electrical circuit that includes the RIO key switch position, the RIO switch sensor, the PTO sensor, the reverse drive sensor, and the ignition cutoff electrical breaker.

The job of the RIO system is to cut off the ignition or turn the engine off whenever the rider starts backing up with an engaged mower deck to insure the maximum safety of those around.

However, you can execute the backing-up maneuver with engaged mower blades, you just have to let the system know that you are paying maximum attention and are fully engaged by moving your ignition key switch to the RIO position and holding it there until you have finished your backing-up motion.

Let’s go through all the possible causes of a reverse problem

We will start from the easiest problem and move progressively to harder issues.

• Your travel pedal (on models with hydrostatic transmissions). The pedal (that is a u shaped bracing that connects both forward and reverse plastic pedals on a teetering mechanism) can get stuck due to some piece of debris in between the pedal and tractor body. Also, the reverse pedal plastic boot can get cracked or damaged and slip down, in which case it will prevent the driver from accessing the full range of pedal motion in reverse mode, limiting the reverse mobility.

• The linkage that connects the travel pedal to the transmission. It can develop a deformity, like say banding, from hush exploitative regimes or simply due to its age, which will prevent the full range of pedal motion because of its distorted geometry, thus limiting the driver from accessing all of the tractor’s potential.

• Electrical issues in your RIO system. If the PTO sensor (that is a part of the ignition key switch which has the PTO position) gets damaged or shorted out, it won’t be able to give proper signals to the circuits or even be giving out false ones. That would cause the system to shut the tractor down even when you do the reversing with engaged mower blades according to the user manual.

• Transmission. If you haven’t been servicing it properly (changing the oil filters and oil in time), it can start to develop some issues. You can suspect a faulty transmission if mobility problems were gradually building up with time; if the problem gets worse as the tractor warms up after a cold start and if you hear grinding or whining noises when you attempt to move the tractor. All transmission problems can basically be boiled down to problems with the hydrostatic unit / the center case, the gear train along with the differential, and the oil level problems due to faulty seals. All these problems take their beginning from bad oil that is full of metal fillings.

Travel pedal and its linkage troubleshooting:

First of all, as it’s always a great idea to keep your equipment clean, take a brush and cleanse the whole linkage system that linked the pedal to the transmission and lies underneath the right foot-weld. Note if there isn’t something stuck in the system.

Also, check if some piece of debris hasn’t stuck between the pedal itself and the body of your tractor.

You should also inspect the integrity of the linkage itself.

If your pedal has a limited range where you cannot engage forward or reverse mode to the full extent, your travel pedal linkage could be bent or deformed. In such a case, you should replace the linkage. 

In case only the revere mode range is limited, you should inspect the reverse pedal plastic boot integrity. Take a look if it hasn’t fallen in. If so, inspect its integrity. Normally the boot shouldn’t be cracked or deformed in any way, and it should sit tightly on the metal pedal.

If there is some sort of problem with your reverse boot, you should replace it. But a temporary solution can be implemented, you can fix its position with a bolt and a washer placed inside the boot’s square hole that would prevent the boot from slipping down the metal pedal rail.

RIO Switch sensor troubleshooting:

If you have found yourself in a situation where your tractor shuts off when you back up with the key in the RIO position, you have an RIO sensor problem. 

In a vast majority of Husqvarna riding mowers, the RIO switch is implemented into the ignition key switch as an additional stage. It also usually plays the role of an RIO sensor. All in one, so to speak.

To test it, take your ignition switch out and test the corresponding pair of contacts with an ohmmeter (for continuity), when the key is in the RIO position.

Hydrostatic transmission problems:

First, let’s start with the easy problem. It can be a worn-out input shaft pulley that has worn-out splints. Typical symptoms are loss of power and immobility.

As we’ve established earlier, bad oil is the usual suspect with the vast majority of transmission problems.

Bad oil can damage the drive shaft and input shaft seals which could cause oil leakage. The insufficient oil level will fail to provide adequate oil pressure inside the hydrostatic system, and it won’t be able to transmit the energy. The typical symptom is winning, complete immobility, or severe loss of power.

Differential and reduction gear-set gears as well as bearings can get damaged by excessive metal filling in the system. The process rapidly spirals as chipped pieces of gears cause even more destruction. Typical symptoms are insatiable mobility, slipping, and grinding noises.

But the most common problem is, worn-out pump and motor pistons and their ports. Again, the premature wear of these is typically caused by bad oil that is full of metal fillings. The typical symptoms are loss of power, slipping, and whining noises; usually, the symptoms get worse as the transmission and the oil inside warm up.

For detailed transmission troubleshooting, it first should be removed from the tractor and taken apart. Only then the differential, reduction gear set, center case, shaft seals, and bearings can be examined and changed.