SZ135-23 Air Spring — Gliderite 4-Bag Rear (ASL4009A / ASL4009N)

A sleeve type air spring for the rear-of-rear position on Gliderite 4-bag air suspension systems. Commonly found on ambulances, emergency vehicles and wheelchair-accessible vehicle conversions on Fiat Ducato (X250/X290), Mercedes Sprinter and Peugeot Boxer chassis — most reliably identified by the SZ135-23 marking on the existing spring. Supplied as a complete assembly.
 
Available in two variants:
 
ASL4009A — SABO equivalent. A direct OE replacement for the Contitech original. UK stock held.
ASL4009N — Contitech OE original. For those requiring a genuine branded replacement.
 
Both variants are direct replacements for the Contitech SZ135-23 reference. The Contitech original carries solid rubber markings on the bellow — if your existing spring is marked SZ135-23 this is the correct replacement.
 
For the front-of-rear position on the same 4-bag system, see [ASL4008A / ASL4008N — SZ135-19]. Air springs on the same axle often wear at a similar rate — replacing in pairs is recommended for balanced suspension performance.
 
Key cross-references: Contitech SZ135-23 | OnAir ASL4009A / ASL4009N
 
Air connector: 6mm push-fit
Construction: Sleeve type — complete assembly
Application: Rear-of-rear on Gliderite 4-bag rear air suspension systems
Max mounting torque: M10 20Nm / M8 15Nm
Available as: SABO equivalent (ASL4009A) or Contitech OEM (ASL4009N)
 
Always verify your existing part number before ordering. Contact our team if you are unsure whether this is the correct replacement for your application.