On Air AL-KO Ducato / Boxer / Relay Rear Semi-Air Suspension Kit
On Air AL-KO Ducato / Boxer / Relay Rear Semi-Air Suspension Kit — AKS3101Z
Is your motorhome's rear sitting too low?
If your Fiat Ducato, Peugeot Boxer or Citroën Relay motorhome scrapes on ferry ramps, steep driveways or inclines when loaded — or the rear simply sits lower than it should when you're carrying extra water, batteries or gear — this is the kit designed to help!
On Air's rear semi-air suspension kit for AL-KO AMC chassis motorhomes gives you on-demand control over your rear ride height. Raise the rear when you need clearance. Level up the rear when parked. Adjust for load. All without altering the original AL-KO suspension — the air springs work alongside it, not instead of it.
Why AL-KO Chassis Motorhomes Have This Problem
The AL-KO chassis is one of the best motorhome platforms available — its low frame design provides a lower floor for larger internal living space of the motorhome than standard alternatives. But that same low frame can often mean the rear sits closer to the ground from the outset. Add any meaningful load — water, batteries, solar equipment, passengers, gear — and the rear drops further. For many owners, the result is regular scraping on ramps, ferries and steep inclines.
This is not a fault. It is the nature of the chassis. The On Air semi-air kit is the aftermarket solution.
What the Kit Does
The air springs are fitted alongside the existing AL-KO torsion beam suspension — nothing is removed. You retain the low floor benefits of the AL-KO chassis while gaining adjustable rear ride height control.
- Raise the rear on demand — clear ferry ramps, steep driveways and long overhang situations
- Level under load — counteract rear drop caused by carrying extra weight
- Independent left/right adjustment — compensate for off-centre loads
- Increased roll stiffness — more stability in crosswinds and when passing high-sided vehicles
- Improved suspension travel — refined ride height leading to increased comfort at all legal payloads
Also a Likely Requirement for Up-Plating
If you're planning to have your motorhome's legal kerb weight increased — to accommodate lithium batteries, extra water or additional equipment — fitting a rear semi-air suspension kit is commonly a requirement of the up-plating process. This kit does not itself increase your legal kerb weight. Up-plating is carried out by a separate specialist third-party company, and whether this kit is required should be confirmed with them.
Is This the Right Kit for My Motorhome?
This kit is designed for AL-KO AMC chassis only — specifically the X250 and X290 Ducato, Boxer and Relay platforms from 2007 onwards, covering single and twin rear axle configurations. It is an aftermarket addition for vehicles with no existing air spring system fitted.
If you are unsure whether your motorhome has an AL-KO AMC chassis, or want to confirm compatibility before ordering, please contact us before purchasing.
Inflation and Controls
Every kit is supplied ready for manual inflation — air is added via a standard tyre inflator or workshop compressor. No on-vehicle compressor is needed for basic operation.
For added convenience, we supply optional compressor and control kits:
- PCP1014R — Compressor and single gauge kit. Both air springs inflate together.
- PCP1016Z — Compressor and dual gauge kit. Independent left and right inflation.
For fully automatic load levelling, the kit is compatible with the On Air Active Advanced Air Suspension Control System (CKA9001Z), which continuously monitors and adjusts ride height using a single height sensor.
Technical Specification
SKU | AKS3101Z |
Platform | X250 / X290 with AL-KO AMC chassis*. * Additional cradle AKS3111Z might be required depending on chassis configuration – ask for more details. |
Year range | 2007 onwards |
Vehicles | Fiat Ducato, Peugeot Boxer, Citroën Relay |
Axle variants | Single or twin rear thru-chassis axles |
Stub axle | 80mm narrow to 140mm wide |
Fitting & Installation
Professional fitting is available at our workshop in Ongar, Essex — call 01277 552030 to arrange. All parts are available for nationwide next day delivery. Full fitting instructions are included with every kit.
An extra chassis cradle may be required depending on your specific vehicle and can be purchased with the kit.