7-Speed Automatic Transmission Assembly for 2009 Mercedes-Benz GL320, GL450

A quick look at your own vehicle makes sure the right transmission shows up:

• Verify vehicle is a 2009 Mercedes-Benz GL320 with the 3.0L V6 Turbo Diesel (OM642) engine.
• Confirm vehicle is equipped with 4Matic All-Wheel Drive.
• Verify current transmission uses Red (MB 236.14) fluid.
• Locate the metal stamp on the transmission case and verify the second line reads 722.902.

What the install really takes — plan and budget with confidence:

Special tools this job needs:

• Mercedes-Specific Scan Tool (XENTRY/DAS, Autel MaxiSys, or Thinkcar 689BT)
• 722.9 Fluid Fill Adapter (e.g., CTA 7415)
• Fluid Transfer Pump
• E-Torx Socket Set
• Torque Wrench
• Mercedes-Benz transmission dipstick tool

Budget for these consumables at install:

• Automatic Transmission Fluid (ATF) meeting MB 236.14 specification
• Transmission Filter & Pan Gasket Kit
• New aluminum oil pan stretch bolts (6 pieces)
• Torque Converter Seal (Input Shaft Seal)
• Transmission Electrical Connector Sleeve
• High-pressure transmission cooler-line flush

What your vehicle’s computers will need after the swap:

What’s involved: SCN Coding / TCM Cloning

The Transmission Control Module (TCM) is built into the internal conductor plate and is a Theft Relevant Part (TRP) cryptographically married to the vehicle's VIN. You must either swap your original functioning conductor plate into this unit, or have a specialist virginize and SCN code the replacement TCM using a Mercedes-Benz STAR/Xentry system.

Pro tips for a smooth first start-up — hand them to whoever does the install:

• Torque Converter Seating: Must rotate and push until it engages and drops backward three distinct times to avoid crushing the internal oil pump.
• Fluid Level Setting Procedure: Must be filled from underneath and checked at exactly 45°C (113°F) using a scan tool to monitor temperature.
• Intelligent Servo Module (ISM) Alignment: Ensure the internal selector lever is physically in the Park detent and matches the electronic command of the module.
• One-Time-Use Bolts: Aluminum pan bolts, flexplate-to-converter bolts, and driveshaft bolts must be replaced and not reused.
• Cooler Line Contamination: A complete high-pressure hot flush of the cooler lines is required to prevent debris from contaminating the replacement unit.

Easy to get right once you know them:

• Using the Wrong Fluid: Using newer MB 236.15 (Blue) fluid or generic multi-vehicle ATF instead of the required MB 236.14 (Red) fluid.
• Reusing the Aluminum Pan Bolts: Reusing stretch bolts leads to them snapping off inside the magnesium case.
• Failing to Address the Immobilizer Lock: Expecting the car to start without swapping the original conductor plate or performing SCN coding.
• Skipping the Torque Converter Drain: Leaving old, contaminated fluid inside the torque converter and cooler lines.
• Attempting to Install a Unit from a Different Model: Assuming a 722.9 from a different engine or chassis model will fit.
• Failing to Replace the Electrical Connector Sleeve: Reusing a brittle sleeve leads to fluid leaks and TCM damage.

Not issues with the units on this page — the manufacturer documented these for every transmission of this family, wherever you buy one. Handy for your installer: