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Fifth Wheel Landing Gear: Issues, Maintenance, and Repairs

We have had two fifth wheels and both had trouble with their landing gear. Tom was able to repair both, but it takes a good understanding of how they work to diagnose the problem. Today we want to share how landing gear systems work some of the general problems you might encounter, and how to repair them.

General Overview of How Landing Gear Systems Work

There are two types of landing gear: electric and hydraulic. Electric landing gear operates using an electric motor driving a set of gears to run the gear. It comes with a control panel or a switch that allows you to control the motor.

electric landing gear on fifth wheel
Electric Landing Gear, you can usually tell by the additional adjuster on the side; this allows quicker setup because direct electric motors generally run slower. This allows the jack to be manually dropped down closer to the ground before applying force.

Hydraulic landing gear relies on hydraulic fluid and a pump system to raise and lower the legs. This system operates similarly to how heavy equipment like diggers work. While it is technically electrically driven, the hydraulic fluid is what moves the rams to lift or lower.

hydraulic landing gear leg on fifth wheel
hydraulic landing gear is always round (although sometimes encased in a square tube); they are completely smooth and do not have adjustments.

Electric Fifth Wheel Jack Issues and How to Solve Them 

Unfortunately, things can go wrong–and we know this all too well and have had multiple problems. Keep reading to learn how to diagnose and solve your electric landing gear issues. 

Fifth Wheel Landing Gear Failure - How to Replace on a Fifth Wheel with a Generator

Motor Failure or Malfunction

The electric motor that drives the landing gear can fail due to overuse, electrical issues, or mechanical wear and tear. Symptoms include the motor not running, making unusual noises, or running but not moving the gear.

Solutions:

First, try inspecting and lubricating the motor. Look for signs of wear or damage. Lubricate the moving parts to reduce friction and heat. You can also try manually actuating the jack. There is almost always an override that allows you to connect a drill to the motor.

If this doesn’t work, you might need to replace the motor. In this case, we recommend consulting the manufacturer’s compatibility guidelines.

landing gear motor

Electrical Issues

You might discover problems with the electrical system, including blown fuses, loose or corroded connections, or faulty wiring. These can also prevent the fifth-wheel stabilizer jacks from functioning properly. 

wiring diagram
This is a generic wiring diagram and yours may be different, but the general concept is here. You will need to check for power at various parts of the circuit to make sure its supplied to the motor when the switch is activated.

Battery Problems 

Since the RV battery often powers the electric landing gear for your fifth wheel, issues like low battery power, a dead battery, or poor battery maintenance can affect the stabilizer jack’s operation. If your jacks are slowing or not able to lift and sound like they are struggling the power supply is probably the problem.

Solutions: 

Start by checking the battery connections for corrosion and ensuring they are tight. If you don’t have a battery monitor or want to directly test the voltage, use a multimeter to measure the battery voltage. When the voltage is low, try recharging the battery. This should happen by plugging the RV in, but if it doesn’t the converter may be off or not functioning.

Should it fail to hold a charge, you may have to replace it. Remember to inspect the battery for physical damage, leaks, or bulging, as these signs indicate a need for replacement. It’s also crucial to assess the performance of your fifth wheel’s charging system, including the vehicle connection and converter, to ensure they are functioning properly.

Switch Problems

The switch that controls the fifth wheel stabilizer jack can malfunction due to wear, dirt, or electrical faults. It can lead to intermittent or non-functional landing gear.

Solutions: 

If your landing gear switch seems faulty, inspect the electrical connections first to ensure there are no loose wires or damaged components. It’s also essential to check the fuse connecting to the landing gear system to help identify potential issues. If the switch is faulty due to dirt or wear, replacement may be necessary. Routine maintenance, including lubrication of moving parts and periodic inspections, can prevent switch problems from arising.

Gearbox Issues

The gearbox that facilitates the movement of the fifth wheel landing gear can experience wear or damage. This can manifest as grinding noises, difficulty in raising or lowering the fifth wheel stabilizer jack, or failure to operate.

Solutions: 

Start by inspecting and greasing the gearbox. Apply grease to the moving parts in the system. This might require removing a panel to look at the gears. Some can be disassembled and others cannot. Sometimes, the gearbox can be rebuilt, but many times, replacing the landing gear is the solution.

Alignment and Adjustment Issues

Misalignment or improper adjustments can cause the landing gear to extend or retract unevenly or with difficulty. Misalignment is usually due to uneven side-to-side pressure, unlevel terrain, or other sideways or backward forces. Its possible the the jacks bind against each other when trying to lift.

Solutions:

If your jacks are binding and not lifting, you may need to use an auxiliary jack to lift slightly allowing pressure to come off the landing gear allowing retraction. To prevent binding the fifthwheel would be as level as possible and resting its weight on wheel cholks. Its important to try and avoid sideways pressure on the jacks and NEVER use the landing gear alone to hold the fifth wheel on an incline.

Its also possible that soft ground allows one jack to sag putting sideways pressure on the rig. Using a pad or piece of wood under the jacks can give them a wider footprint and prevent sinking.

Stabilized trailer
When unhitched, your fifth wheel stabilizer jack will keep your camper stable.

Overloading

Exceeding the weight limit of your fifth wheel’s landing gear can cause strain on the motor and mechanical parts, leading to premature failure.

Solutions: 

Please adhere to weight limits and always follow the manufacturer’s weight capacity guidelines. This prevents strain on the landing gear components and increases its longevity. Typical parts that may fail due to exceeding weight limits include the gears and gearbox, landing gear legs, cross shafts, braces and supports, and mounting brackets. 

Motor Turns But Will Not Lift

When a shear pin breaks, the landing gear will not move, but the motor will spin. If you are experiencing this problem where you can hear the motor but get no movement, the gear has probably broken a shear pin.

Solutions: 

Most landing gear do not have limit switches, but shear pins that will break if the gear is overextended. This can also happen if they are retracted too far. If this year’s pin breaks, the gear will no longer move. Shear pins are usually located on the shaft where the motor connects to the gearbox and must be replaced before the gear will work again.

Pro Tip: Learn more about how RV stabilizers work before you hitch up and head out.

Hydraulic Fifth Wheel Jack Issues and How to Solve Them 

Hydraulic landing gear is much faster and rated for higher weights, but they have their own set of problems. The general concept of hydraulic systems is that a pump is used to move a cylinder with fluid; problems anywhere in the system can cause an issue. Hydraulic systems can be complicated, and because they hold the weight of the RV and operate at very high pressures, they can be dangerous. If you are not confident in your abilities to work on these systems please hire a professional.

hydraulic system diagram

Hydraulic Fluid Leaks

One of the most typical problems is leaking hydraulic fluid, which can result from loose connections, damaged hoses, or seals. This can lead to reduced pressure and inefficiency in operating the landing gear. 

Solutions:

Start by locating the source of the leak. This can be challenging if the hose is run in an inaccessible space of the RV. If the leak is occurring at a junction, it’s possible you will be able to tighten the connection. If it’s along a hose, the entire hose will probably need to be replaced.

If you choose to do the repair, you will need an additional understanding of hydraulic systems and how to reprime. You may also need to raise the fifth wheel to relieve pressure on the jacks. Any local hydraulic shop can make a new hose.

Air in the Hydraulic System

Trapped air in the hydraulic system can cause the landing gear to operate erratically or become less responsive. It may also lead to a spongy feeling while operating it or weird pinging sounds.

Solutions

If this is the case, you’ll need to remove air from the system by bleeding it. Usually, this is accomplished by moving the jacks to their extreme. To do this you may need to park over a dip so the jacks can extend fully. This will force air back to the reservoir and out of the system.

Pump or Motor Failure

The hydraulic pump is crucial for the landing gear’s operation. If the pump fails,, the jacks will not move. Diagnosing and correcting problems with the system can be quite complicated but here are some steps to help diagnose what the problem is.

hydraulic electric pump

Solutions:

First, determine if the problem is electrical. If the pump does not run, check to make sure it is receiving power. If it is and not running, the pump will need replacement. If there is no power, check the connections and control panel or switch and fuse. Follow the circuit back to the battery to make sure all connections and fuses are good.

If the motor is turning but no movement then there could be many problems. Lets take a look at a few more.

Valve Malfunctions

Valves control the flow of hydraulic fluid. If they clog, corrode, or malfunction, they can affect the extension and retraction of the landing gear. We had to replace a valve or two over the years that were leaking.

Solutions: 

Once again start with the electrical. Determine if the electric valve is being supplied by power when it should. Use a power meter to check for voltage across the terminals when activating the hydraulic circuit. If no power the control panel, switch or a fuse may be bad. If it is receiving power and not activating then the coil may need to be replaced. Its also possible to manually overide the valve by turning a nob or using a hex to open it. WARNING – If you open the wrong valve the landing gear could collapse!

hydraulic valve
RV Landing gear hydraulic valves

Seal Deterioration

The seals in the hydraulic system can wear out or degrade, leading to leaks and loss of pressure. 

Solutions: 

hydraulic landing gear seal fail
The external seal on this landing gear has failed, the inside seal is what holds the fluid however. If it fails it will leak and drop.

There are many seals in a hydraulic system, and if any of them fail, leaking and loss of pressure can cause the jacks to drop. We had to replace seals in our many jacks and the process will vary from RV to RV, but the piston with the seal will need to be removed. Here is the video of how we replaced ours.

Fixing our Leaking Sinking Hydraulic Landing Gear on our Fifthwheel in a Walmart parking lot!

Inadequate Hydraulic Fluid Levels

Low hydraulic fluid levels usually result in air in the system. As mentioned before, the air will need to be bled. If the fluid levels are low, there is a chance that the system has a leak. Before replacing fluid, check the system and try to determine where the fluid went.

Electrical Issues Affecting Hydraulic Controls

For systems where hydraulic functions are controlled electrically, issues like faulty wiring, dead batteries, or blown fuses can impact the operation of the landing gear.

Solutions: 

The culprit could be as simple as a blown fuse or as expensive as a faulty battery. Start by checking the fuses. If none are blown, visually inspect the wiring for signs of damage or other issues. If all seems well, your battery might be dead. In this case, check the voltage with a multimeter and charge it if needed. If your battery is unable to hold a charge, you may need to replace it. 

fifth wheel stabilizer jack
Whether you use an electric or hydraulic leveling jack, you will want to know the ins and outs of how to use it for optimal performance.

Environmental Damage 

Rusting hydraulic rams can cause leaks. Usually, the thin coat of hydraulic fluid left on the ram will prevent corrosion, but if they are left down long enough, they will begin to rust.

Solutions: 

Corrosion on cylinders can not be completely removed without damaging the cylinder. It can be brushed off with a wire brush or polished with a compound polish. If the cylinder is leaking too bad it might need to be replaced. Preventing further damage is usually the best that can be done.

If the landing gear is going to be left down for an extended period of time, we highly recommend applying anti-corrosion on the surface. This can be any grease or wax. For our hydraulics, we apply a thin layer of fluid film once per year when we store it.

Pro Tip: Leveling your RV doesn’t need to be complicated! Get the inside scoop on What You Need to Know About Auto Leveling System for RVs.

Become an Expert on Your Fifth Wheel and Avoid Getting Stranded

We know these systems can be frustrating when they go wrong and can leave you stranded. If you have a general understanding of how they work, however, some problems can be quickly resolved.

Do you have any questions about fifth wheel landing gear issues? Drop them in the comments below!

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About Tom Morton

Tom, a Pacific Northwest native, is our technical genius. Born in Washington and raised in Alaska before settling in Michigan. He's the man who keeps our operation running, both figuratively and literally.

With a background in Electrical Engineering, Tom specializes in RV solar systems and lithium batteries. He made history as the first documented individual to use a Tesla battery module as an RV battery. Tom has personally assisted countless RVers with system installations and has educated thousands more through his videos and articles.

Cinematography is another of Tom's passions, showcased in his work on the Go North series. You can see his camera skills on display in The RVers TV show on Discovery Channel and PBS where he also stars as a co-host.

Tom's mechanical expertise extends beyond RVs to boats, planes, and all things mechanical. He's renowned for taking on maintenance and repair projects single-handedly and is often spotted underneath RVs, making him the technical backbone of our endeavors.

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Charles Land

Thursday 21st of March 2024

We visit our nephew each fall and he has a driveway sloping down from his house - probably a 10% grade - pretty steep so the landing gear has to raise the trailer front 18 inches. I found I needed to let the trailer roll onto the chocks far enough that there is a tiny bit of backward movement when the hitch releases. As the trailer front rises to almost fully extended the angle of the landing gear changes, trying to push the trailer bachward a tiny bit. If I have done the chocks right, trailer can move a little without stressing the landing gear. Learned this the hard way 1st time. Corkscrewed the the rod that spins to raise and lower.

Tom and Caitlin Morton

Wednesday 27th of March 2024

Ahhh, Yea that presssure needs to be removed. But hey we saw some people once with hydralic jacks fold forward because it was such a steep hill!

martin

Wednesday 20th of March 2024

repairs - would be great if there were spare parts ... I had to replace the whole motor+gear only because the hall sensor was defect and the sensor alone is not available :-(

Tom and Caitlin Morton

Wednesday 20th of March 2024

Ugh Right! We had to replace the entire units on our first rig too because the parts were not available.