Essential Guide to Gas Strut Replacement
Gas strut replacement is a common maintenance task across many applications, from vehicle tailgates and bonnets to cabinets, access hatches, and industrial enclosures. Gas struts (also known as gas springs) are designed to lift, support, and hold open moving panels safely and smoothly.
Over time, gas struts lose pressure and performance. When this happens, doors may no longer stay open, become difficult to lift, or drop unexpectedly. Replacing worn gas struts at the right time improves safety, convenience, and overall functionality.
This guide explains how gas struts work, how to identify when replacement is needed, how to measure and choose the correct strut, and how to install new ones safely—whether for automotive or universal applications.
Understanding Gas Struts
Gas struts are mechanical components that assist with lifting and holding loads. They are widely used in both automotive applications (car boots, tailgates, bonnets) and universal applications such as cabinets, storage boxes, hatches, and access panels.
A typical gas strut consists of:
-
A sealed cylinder filled with pressurised gas
-
A piston rod that moves in and out of the cylinder
-
End fittings (such as ball joints or eyelets) for mounting
The controlled force provided by the gas allows panels to open smoothly and remain supported without sudden movement.
Because gas struts operate under pressure, their performance gradually decreases with use. Environmental factors such as temperature, load weight, and usage frequency also affect lifespan.
What are gas struts?
Gas struts are self-contained lifting devices that reduce manual effort when opening or holding panels. They are designed to:
-
Assist lifting heavy or awkward loads
-
Hold panels securely in an open position
-
Provide smooth, controlled motion
How do gas struts work?
Gas struts work by using compressed gas sealed inside the cylinder. When the strut is compressed, internal pressure resists the movement of the piston rod. When released, this pressure generates force that pushes the rod outward.
For best performance and durability, gas struts are typically installed with the rod facing downward. This helps keep internal seals lubricated.
Signs You Need a Gas Strut Replacement
Gas struts rarely fail suddenly. Instead, performance declines gradually. Recognising early warning signs helps prevent inconvenience and safety risks.
Common indicators include:
-
Panels no longer staying open
-
Increased effort required to lift
-
Sudden dropping or unstable movement
-
Visible oil residue on the strut body
Importance of timely replacement
Replacing gas struts at the right time:
-
Improves safety
-
Prevents damage to hinges
-
Restores smooth operation
How to Measure Gas Struts for Replacement
Correct measurement is essential when replacing gas struts. Even small differences in size or force can affect performance.
When measuring, consider four key factors:
-
Length (Extended)
-
Stroke
-
Force (Newton rating)
-
End fittings
Step-by-step measurement guide
-
Extended length:
Measure the strut fully extended, from centre of fitting to centre of fitting. -
Compressed length & stroke:
Measure the strut fully compressed. The difference between extended and compressed length is the stroke. -
Force rating (Newton – N):
The force is usually printed on the strut body (e.g. 400N, 800N).
As a general rule: 100N ≈ 10 kg of support force
Choosing incorrect fittings is a common cause of installation issues.
Choosing the Right Gas Strut
Selecting the correct gas strut involves balancing all measurements—not just length.
-
Force too low: panel won’t stay open
-
Force too high: panel opens too aggressively or stresses hinges
Gas struts should always be replaced in pairs where two struts are used. Replacing only one can cause uneven force and premature failure.
Installing New Gas Struts
Installing new gas struts is generally straightforward, but safety precautions are essential.
How to install gas struts safely
-
Secure the panel or lid to prevent sudden closure
-
Use a prop or have assistance if needed
After installation, test operation slowly before normal use.
Special Considerations for Automotive and Universal Applications
While gas struts are widely used, load requirements differ by application.
-
Automotive applications (tailgates, boots, bonnets) often require higher force ratings and precise fitting alignment.
-
Universal applications (cabinets, hatches, enclosures) may prioritise smooth control and compact sizing.
Conclusion
Gas strut replacement is a practical and cost-effective way to restore safe, smooth operation. By understanding how gas struts work, recognising signs of wear, and selecting the correct replacement, you can avoid common issues.
If you are unsure about measurements, force ratings, or fittings, contact our team before ordering to ensure the best result.
FAQs About Gas Strut Replacement
How long do gas struts last?
Typically 5–10 years, depending on usage, load, and environment.
Should gas struts be replaced in pairs?
Yes. Replacing both ensures balanced force and proper operation.
How do I choose the correct force rating?
Check the original strut rating. Remember: 100N ≈ 10 kg.
Can I replace gas struts myself?
In most cases, yes—provided safety precautions are followed and the panel is secured before removal.
What happens if I choose the wrong gas strut?
Incorrect force or fittings can cause instability, poor performance, or damage to the mounting points.
