Ineos Grenadier & Quartermaster Air Suspension Conversion
The Ineos Grenadier was built for genuine off-road use and hard work, and many owners load it accordingly. Towing, roof tents, expedition gear, workshop equipment and heavy accessories all add weight at the rear, and the standard coil springs compress under it. The rear sits lower, ground clearance drops, and the vehicle no longer sits at the height it was designed to run at.
On Air Suspension have designed an air suspension conversion specifically for the Grenadier. It's available for both the Station Wagon and the Quartermaster double cab pick-up.
What is the Grenadier air suspension conversion?
Our in-house designed kit replaces the Grenadier's standard coil springs with an air-spring system engineered for the Grenadier's chassis geometry, not adapted from another platform. It comes in two configurations:
Rear air suspension: replaces the rear coils with air springs and holds the rear at a set ride height automatically as load changes. Fits the Station Wagon and Quartermaster.
4-corner conversion: replaces the coils at all four corners and adds driver-selectable ride height. Available in Station Wagon and Quartermaster versions.
Rear kit: On Air Active included as standard
The rear conversion includes On Air Active, our own electronic control system. It's included as standard, not an add-on.
An ECU reads a single height sensor on the rear axle and adjusts the air springs to hold the rear at a set ride height as load changes. It runs as a standalone system, independent of the vehicle's electronics. A built-in adjustment delay means it settles to the load instead of reacting to every bump or short stop. A dashboard dump button incrementally deflates the rear fully for low-access loading while ignition off and ride height returns automatically once you drive off.
The rear kit holds a set ride height. Driver-selectable ride height is part of the 4-corner conversion.
Learn more about On Air Active →
4-corner conversion: selectable ride height
The 4-corner conversion fits air springs at all four corners. You select the ride height from the cab: lowered for cabin access and loading, standard for everyday driving, or raised for extra ground clearance off-road. Because every corner is on air, the system can also level the vehicle under uneven loads.
Grenadier Quartermaster
The Quartermaster carries its load differently from the Station Wagon. Payload sits in the load bed, over and behind the rear axle. Canopies, hardtops, tool storage, water tanks and trailer nose weight all compress the rear coils, and a heavily loaded Quartermaster can sit noticeably lower at the back.
Both kits are available for the Quartermaster double cab:
Rear air suspension (AKF1751Z): holds the rear at a set ride height as load goes into and comes out of the bed, with a dump switch to lower the rear for loading.
4-corner conversion (AKF1251Z): the full 4-corner system, built for the Quartermaster, with driver-selectable ride height at all four corners.
What's included
Both kits:
Bespoke On Air / SABO air springs with heavy-duty solid pistons, matched to the Grenadier's suspension geometry
AMK compressor, the same unit used in our Defender conversions
Stainless steel height sensor brackets
Grenadier-specific rear chassis-to-compressor bracket and mid tank mounting with reinforcement
Grenadier-specific bump stops and top brackets
All fixings, nylon tubing, fittings and hardware
Rear kit (AKF1751Z):
On Air Active S1.1 control system: ECU, single rear height sensor, valve block, wiring harness and dashboard dump switch
4-corner kits (AKF1250Z / AKF1251Z):
Full 4-corner control system with cab-selectable ride height
How it works
Ride height held under load: the air springs are inflated to support the load, so the rear stays at its set height instead of compressing as the coils would. This applies up to the vehicle's GVW.
Automatic levelling on the rear kit: the ECU monitors rear ride height and adjusts the air pressure as load is added or removed.
Dump function: the rear deflates fully on demand for low-access loading.
Selectable ride height on the 4-corner kits: lower, standard and raised settings, chosen from the cab.
Reversible design: the conversion is engineered around the Grenadier's existing mounting points.
Is rear sag a problem on your Grenadier?
If your Grenadier sits noticeably lower at the rear when it's loaded, the rear coils are compressing under the weight. This happens when towing, carrying a roof tent and expedition gear, or running heavy accessories or a loaded Quartermaster bed. Rear sag reduces rear ground clearance and changes the departure angle.
The rear kit replaces the coils with air springs that are inflated to support the load, holding the rear at its set height whatever you're carrying.
Designed and built by On Air Suspension
Every On Air Suspension kit begins on our CAD systems. Our in-house engineering team designs each solution from scratch, prototypes using 3D printing, and validates it through physical installation and testing at our Ongar, Essex workshop before the kit reaches a customer. Brackets and structural components are manufactured to our specifications by trusted UK suppliers. We don't fit other people's kits; we build our own.
Kit Options
SKU
Configuration
AKF1751Z
Ineos Grenadier Rear Air Suspension (Station Wagon & Quartermaster)
AKF1250Z
Ineos Grenadier Station Wagon 4-Corner Full Air Suspension
AKF1251Z
Ineos Grenadier Quartermaster 4-Corner Full Air Suspension
Fitting
We offer a full fitting service at our workshop in Ongar, Essex. Fitting typically takes 2–3 days for the rear kit and 3–4 days for the 4-corner conversion. Call us on 01277 552030 to discuss your requirements.
FAQ
Should I choose the rear-only kit or the 4-corner conversion? For load-carrying and towing, the rear kit (AKF1751Z) covers most Grenadiers. The loads that change ride height (towing, rear-mounted equipment, expedition gear, a loaded Quartermaster bed) act on the rear axle, and the rear kit holds ride height under exactly those loads. It includes On Air Active as standard: an ECU levels the rear automatically from a single height sensor, with a dump switch for low-access loading. The 4-corner conversion adds driver-selectable ride height at all four corners: lowered for access, raised for ground clearance, and level under uneven loads. If you're unsure, call us and describe how you use the vehicle.
Does the rear kit include a control system, or is that an extra? The rear conversion includes On Air Active, our own control system, as standard. It isn't a separate purchase. An ECU reads a single rear height sensor and adjusts the air springs to hold the rear at a set height as load changes, and a dashboard dump switch deflates the rear fully for loading. It runs independently of the vehicle's electronics.
Do you make a kit for the Grenadier Quartermaster? Yes. The rear kit (AKF1751Z) fits both the Station Wagon and the Quartermaster double cab. The 4-corner conversion has a dedicated Quartermaster version (AKF1251Z) alongside the Station Wagon version (AKF1250Z). Choose your body type in the kit selector.
Does the kit help when towing? Yes. Towing is one of the rear kit's main uses. Trailer nose weight sits on the rear axle and compresses the standard coils, dropping the rear. The rear kit's air springs are inflated to support that load, holding the rear at its set ride height.
Does the kit increase my Grenadier's payload or towing capacity? No. The kit manages how the vehicle carries its rated load, holding ride height up to the vehicle's GVW. The plated payload, GVW and towing limits are unchanged.
How long does fitting take? Fitting at our Ongar workshop typically takes 2–3 days for the rear kit and 3–4 days for the 4-corner conversion. Is anyone else making an air suspension conversion for the Grenadier? On Air Suspension designed and built the first air suspension conversion for the Grenadier platform, and remains the leading specialist for it. The rest of the aftermarket offers coil and damper upgrades rather than air conversions.