What Are Lift Supports and When Do You Need Them?

What Are Lift Supports and When Do You Need Them?

Lift supports are nitrogen-charged cylinders that use internal gas pressure to provide controlled force for opening and holding heavy vehicle components.

Lift supports, often referred to as gas struts or gas springs, function by using high-pressure nitrogen gas to push against a piston rod. This force is calibrated to counterbalance the weight of a hatch, boot, or bonnet, effectively reducing the physical effort required to lift them. When functioning correctly, they allow for smooth, hands-free operation and secure hold-open positioning.

How do I know my lift supports are failing?

Failing supports show symptoms like sagging lids, difficulty lifting under cold temperatures, or audible hissing from the cylinder seals.

The most obvious sign of failure is the inability to keep a tailgate or bonnet in the fully open position. You may notice the component drifting downward slowly, or worse, snapping shut without warning. These symptoms are frequently amplified in colder climates where internal gas pressure drops naturally.

• Visible oil weeping around the piston rod seal
• Corrosion or pitting on the polished rod surface
• The lid drops noticeably faster as outside temperatures decrease
• Resistance disappears entirely during the final stage of opening

Why is it necessary to replace supports in pairs?

Replacing both lift supports simultaneously ensures symmetrical force distribution and prevents mechanical stress on the hinge assembly.

I frequently see customers replace only one unit, only to find the new, stronger strut twists the lid frame. This is because the old strut has lost significant pressure, forcing the new one to bear the load unevenly. Over time, this imbalance leads to premature hinge fatigue and potential structural misalignment of the body panels.

How Do I Measure Lift Supports for Replacement?

To measure accurately, record the extended length eye-to-eye and the compressed length, then note the force rating in Newtons or lbs.

How do I measure the extended and compressed lengths?

Measure the distance from the centre of one mounting point to the other while the support is at its maximum and minimum extensions.

Accuracy is the difference between a functional replacement and a part that won’t fit your car boot mechanism. You must measure the distance between the centres of the end fittings when the support is fully extended. If you are ordering new parts, verify these dimensions match the manufacturer’s spec sheet exactly.

How do I identify the correct Newton force rating?

The force rating is usually printed on the body of the strut in Newtons (N) or pounds (lbf) and is essential for safe operation.

It is a common error to purchase a support based solely on its physical dimensions while ignoring the force rating. If you select a strut with too much force, you risk bending your bonnet brackets or damaging the glass of your hatchback. Always use our gas spring force calculator to verify your requirements before finalizing an order.

What Are the Best Practices for Installation?

Proper installation requires cleaning mounting studs, verifying the orientation, and ensuring the retaining clips are fully seated.

Does mounting orientation matter for lift supports?

Most lift supports must be mounted with the rod end pointing downward to ensure internal oil lubricates the primary seal properly.

Failure to follow the recommended orientation leads to seal dehydration, resulting in rapid loss of gas pressure. Unless a specific part is designed for universal orientation, always keep the rod end pointing toward the floor. If you are struggling with a specific fitment, refer to our gas strut compatibility checker to confirm the orientation requirements.

What should I check before attaching the new struts?

Inspect the ball studs for rust or wear, and ensure the new retaining clips snap firmly into place to avoid accidental detachment.

A new strut is only as secure as the mounting stud it attaches to. Use a wire brush to remove debris from the ball studs and apply a light coat of high-quality grease if the environment is prone to road salt. Never force the end fitting onto the stud; it should click into place with minimal resistance if the alignment is correct.

FAQ: Common Questions About Lift Supports

Get quick answers to common troubleshooting and specification questions regarding gas-charged lift supports in automotive and industrial use.

Can I recharge a lift support that has lost pressure?

No, lift supports are sealed units and cannot be recharged or repaired once they lose their nitrogen gas charge through the seal.

What is the typical lifespan of a lift support?

A quality lift support is generally rated for 30,000 to 50,000 cycles, translating to 5 to 10 years of use under normal conditions.

Are aftermarket lift supports as good as OEM?

Modern aftermarket lift supports often meet or exceed OEM specifications if you purchase from reputable manufacturers with quality control.