2019 — 2026
3.0L Inline-6 Turbo Diesel (OM656) - G400d
Diesel
Check the 9G-TRONIC transmission at low speeds | Observation: While driving through a suburban area, pay close attention to the 1st to 3rd gear shifts. If the transmission feels jerky or hesitant, it's worth checking if the software has been updated or if the transmission fluid service history is complete.
Inspect the panoramic sunroof and window seals | Observation: Before heading out, inspect the rubber seals around the doors and sunroof for any signs of cracking or perishing. In our NZ climate, UV exposure can sometimes lead to wind noise or dampness if these seals aren't regularly conditioned.
Listen for suspension clunks on uneven surfaces | Observation: Try to find a slightly bumpy road and listen for any knocking noises from the front end. The G-Class W463A features complex independent front suspension; checking the bushings and sway bar links for play is a sensible step.
Cycle through the MBUX infotainment and driver displays | Observation: Take a moment while stationary to toggle through all the menu screens and ensure the dual-screen setup is responsive. It is helpful to confirm that all digital features are connecting correctly, as electrical gremlins are occasionally seen in high-tech interiors of this generation.
Usually marks the first major service interval where transmission fluid and differential oils are prioritized.
A common point where owners might look into a comprehensive health check, including potential suspension component inspection and a deep dive into the diesel particulate filter (DPF) status.
An age where you might consider a thorough preventative look at the ancillary belt systems and coolant hoses.
Keep the AdBlue levels topped up consistently to maintain optimal exhaust gas treatment.
Stick to the manufacturer-recommended interval for engine oil changes using the specific MB-approved synthetic oil.
Ensure the air intake systems are kept clean, especially if the vehicle sees any light gravel or off-road use.
Regularly clean and treat the rubber window and door seals to keep them supple and weather-tight.
Monitor the brake pad thickness, as the weight of the G-Class can lead to faster wear than a standard sedan.
Estimated repair costs if issues arise
Because the G400d has sophisticated locking differentials, regular fluid changes are key to longevity. If this has been missed in the service history, you might eventually need to budget for a comprehensive flush and fluid replacement.
Given the G-Class is a heavy vehicle, the brakes work quite hard. Depending on the car's history, you might eventually need to budget for a full set of pads and rotors as they reach their wear limits.
If the vehicle is equipped with adaptive damping, these complex components provide a superb ride. In cars of this age, it's common to consider that these components will eventually require professional inspection or replacement to maintain that plush factory feel.
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Disclaimer: This report is generated with the assistance of AI analysis based on verified automotive data. While we strive for 100% accuracy, enthusiasts should always conduct physical inspections and consult service records. View Full Disclaimer