MARCH 14, 2025
Is My Liftgate a Power Down or Gravity Down?
Knowing whether you have a power-down or a gravity-down system when using a liftgate is crucial to maintain it, diagnose a problem, and use it efficiently.
Most liftgate users are not aware of the differences these systems have, and getting confused when diagnosing a problem or buying new parts is common.
In this guide, we guide you through the most basic ways to know what system your liftgate has and why it is crucial.
- What is a Power Down compared to a Gravity Down Liftgate?
- How to Know If Your Liftgate Is Power Down or Gravity Down
- Why Does it Matter?
- Conclusion
- Step 2: Removing the Old Cylinder
- Step 3: Installing the New Cylinder
- Step 4: Final Checks Before Powering On
- Finding Liftgate Repair Near Me
- Conclusion
What is a Power Down compared to a Gravity Down Liftgate?
Liftgates use a hydraulic system to raise and lower the platform. All liftgates though, do not operate the same way when lifting or lowering the platform. Here are the differences.
Power-Down Liftgates
Use hydraulic pressure to raise and lower the liftgate. The hydraulic pump and motor activate when the gate goes down, pushing fluid throughout the system to control the descent.
Gravity-Down Liftgates
Use hydraulic pressure to raise the platform but use gravity to lower it. Once you activate the "DOWN" function, a valve is released to allow hydraulic fluid to flow to the cylinders, and it drops downward by its weight.
Each system has its benefits in different areas. Power-down systems provide a more controlled descent, making them useful in extreme cold weather when hydraulic fluid thickens up. Gravity-down systems use less power and put less wear and tear on the motor.
How to Know If Your Liftgate Is Power Down or Gravity Down
If you’re not sure of your liftgate type, here’s a few ways to know it:
1. Listen to the Motor When Lowering the Liftgate
If the motor is engaged when in a downward position of the liftgate, you've got a power-down system. If you've got the liftgate moving down without using a motor, you likely have a gravity-down system.
2. Inspect the Power Unit
Generally speaking, the visual appearance of a liftgate is a poor indicator to determine whether you have a power or gravity down liftgate. Identifying by eye would take a massive amount of knowledge and experience on a wide variety of lift gates, and even with that, it may be impossible.
However, on some smaller gates, like single function (raise/lower only) tuck-unders or smaller rail lift gates with manual closing platforms, it’s possible to compare the spool valve count to determine power or gravity down operation.
In these cases, locate the power unit, check its configuration to specs or pictures online to know your system type.
3. Inspect the Hydraulic Hoses
Hydraulic hose connections also provide a clue to your liftgate type:
* Power-down systems typically include two high-pressure hydraulic hoses to the lift cylinders.
* Gravity-down systems typically include one high-pressure hose and a nylon return hose or a breather plug on the lift cylinder.
Inspecting these connections can tell you if or if not your system is using hydraulic power to descend.
4. Inspect the Manufacturer’s Material of the Liftgate
Liftgate manufacturers typically note in their documentation, on their website, or in their product description if a liftgate is power-down or gravity-down. If you still have documentation or know the serial number, you can get in touch with us or the manufacturer to confirm it.
5. Call a Liftgate Expert
If you’re still in the dark, it’s always a better option to call a liftgate expert. Here at LiftGateMe, our team is experienced in determining liftgate types and providing you with accurate parts for your system. Simply send us the serial number of your liftgate, and our experts can look up if it’s a power-down or a gravity-down system. Contact us now!
Why Does it Matter?
Knowing your liftgate type is important for multiple reasons. Here are the most relevant.
Ordering the Correct Parts
Replacement parts such as valves, solenoids,cylinder, power units and hydraulic hoses, differ between power-down and gravity-down systems. Installation failures and in-operation breakdowns can be caused by ordering an incorrect part.
Maintenance & Troubleshooting Correctly
Knowledge of your system permits you to diagnose issues correctly. Examples are a stuck valve causing a sudden failure of a gravity-down liftgate to lower, or a power-down liftgate having a problem with hydraulic fluid.
Prevention of Redundant Repairs
Most users mistakenly believe that a problem in a liftgate is a bad motor, when their gravity-down system is actually having a blocked or failed spool/locking valve. Knowledge of your system prevents unnecessary repairs and parts replacement.
Weather Considerations
In cold weather, power-down systems can be more reliable, as thickened hydraulic fluid is a problem that sometimes affects gravity-down systems. Knowledge of your system permits you to take preventive action in extreme temperatures.
Conclusion
Determining whether your liftgate is power-down or gravity-down is simpler than you think. By listening to the motor, looking at the power unit, observing hydraulic hoses, and cross-referencing manufacturer specifications, you can easily know your liftgate type.
Knowing your liftgate system means smooth operations, fewer breakdowns, and the security of having the correct parts when you need them.
Need more help? Contact LiftGateMe today with your model and serial number, and our team will assist you in getting the correct information and parts for your liftgate.
Have a question? We'd love to hear from you.
No liftgate serial number? Click here for a visual guide to locate it, then contact us.
