Unity 13-512900 Air Suspension Shock - Rear

OEM Style Rear Air Shock for Mercedes-Benz

Restore rear suspension control with the Unity OEM Style Electronic Air Suspension Shock Absorber, part number 13-512900. This rear air shock is built to match OEM collapsed length, extended length, and shock stroke specifications for a direct-fit replacement on select Mercedes-Benz SUVs and crossovers with Adaptive Damping Suspension (ADS).

Unity Automotive draws on more than 40 years in the aftermarket and a broad suspension catalog to produce replacement parts that meet or exceed OEM standards. The 13-512900 is an OEM-style electronic gas shock absorber for rear applications, made for drivers who need factory-correct suspension geometry and electronic damping function.

Key Features

• OEM style electronic air suspension shock absorber for rear suspension service
• OEM collapsed length, extended length, and shock stroke for factory-matched fitment
• Electronic gas shock design for vehicles equipped with Adaptive Damping Suspension (ADS)
• Direct replacement for select Mercedes-Benz GL-Class and M-Class rear applications
• Unity Automotive part number 13-512900

Detailed Description

Unity 13-512900 is engineered for rear suspension use on 2006-2012 Mercedes-Benz models with ADS, including GL350, GL450, GL500, GL550, GL320, ML350, ML450, ML550, ML320, and ML500 applications. It is a fitment-specific replacement for the rear electronic gas shock used in air suspension systems, helping maintain the original ride height, damping response, and suspension travel expected from the factory setup. This part cross-references Focus Auto Parts 99057 for the same application.

Use this part when servicing a Mercedes-Benz GL350, GL450, GL500, GL550, ML350, ML450, ML550, GL320, ML320, or ML500 rear suspension equipped with Adaptive Damping Suspension. The part number 13-512900 is also referenced by multiple OE interchange numbers for the same application.

What It Helps Fix

• Rear suspension sag or uneven ride height
• Excessive bouncing, harshness, or reduced damping control
• Warning signs from a worn electronic air shock on ADS-equipped vehicles
• Loss of factory ride quality in Mercedes-Benz GL-Class and M-Class rear suspension
• Suspension noise or instability caused by a failing rear shock absorber

Installation Notes and Tips

Confirm the vehicle is equipped with rear Adaptive Damping Suspension before ordering. Verify the original shock dimensions and connector style against the OEM specifications listed for collapsed length, extended length, and shock stroke. After installation, inspect the air suspension system for leaks, worn mounts, and related wear items so the new shock can operate correctly.

Quality Assurance

Unity Automotive has over 40 years of aftermarket manufacturing experience and offers extensive suspension coverage across more than 1500 unique SKUs. The 13-512900 is produced to meet or exceed OEM standards for fit and function on the listed Mercedes-Benz rear applications.