2021 Mercedes-Benz G-Class
Vehicle Specs & Maintenance Data
The 2021 Mercedes-Benz G-Class maintenance specs on this page cover the key fluids, torque values, and wear items you need for routine service. Use these numbers as a quick reference when performing oil changes, tire rotations, brake jobs, and other scheduled maintenance on your Mercedes-Benz G-Class.
For oil changes, the 2021 Mercedes-Benz G-Class takes 0W-40 Full Synthetic motor oil with a capacity of 8.5 quarts. Brake fluid type is DOT 4, the recommended coolant is MB 325.0 (Blue, silicate-free), and transmission fluid is MB 236.14. Always use the manufacturer-recommended fluids to maintain warranty coverage and engine longevity.
When mounting wheels on the Mercedes-Benz G-Class, torque the lug nuts to 96 ft-lbs using a calibrated torque wrench. Over- or under-torquing can lead to warped brake rotors or loose wheels. Re-torque after 50 to 100 miles on newly installed wheels.
Owners of the 2021 Mercedes-Benz G-Class have reported 5 common issues including "Front Axle Clunking and Steering Vibration", "Electrical System Complexity Faults" and "MBUX Infotainment Freezing". Scroll down to the Diagnostics tab for detailed descriptions, solutions, and estimated repair costs.
Specifications on this page are compiled from multiple publicly available sources including manufacturer documentation, NHTSA data, and automotive databases. Always cross-reference with your owner's manual or official factory documentation before purchasing parts or performing any service.
The 2021 Mercedes-Benz G-Class uses 0W-40 Full Synthetic motor oil (8.5 qt capacity), requires lug nuts torqued to 96 ft-lbs, takes DOT 4 brake fluid.
Manufacturer-recommended maintenance schedule for the 2021 Mercedes-Benz G-Class. Always verify intervals against your owner's manual.
Enter a diagnostic trouble code to see causes, symptoms, and fixes for the 2021 Mercedes-Benz G-Class.
Common problems reported by 2021 Mercedes-Benz G-Class owners, with recommended fixes and estimated repair costs.
Front Axle Clunking and Steering Vibration
The G-Class's solid front axle with recirculating ball steering develops clunking noises and steering wheel vibration, particularly at highway speeds. The steering damper and drag link ball joints are the primary wear points.
Replace the steering damper, drag link, and worn ball joints. A front-end alignment is required after steering component replacement. Some owners upgrade to aftermarket heavy-duty steering components.
Est. Cost: $800 - $2,500Electrical System Complexity Faults
The modern G-Class is among the most electronically complex vehicles Mercedes-Benz produces, resulting in frequent electrical faults including random warning lights, sensor malfunctions, and module communication errors.
Dealer diagnostic scan to identify specific fault codes and affected modules. Software updates address many issues. Individual control module replacement for hardware faults. Battery registration and coding required after battery replacement.
Est. Cost: $200 (software update) - $3,000 (module replacement)MBUX Infotainment Freezing
The MBUX infotainment system freezes, reboots, and loses connectivity with paired phones. The large central display and digital instrument cluster can both go black simultaneously, losing access to vehicle settings and climate controls.
Mercedes-Benz over-the-air or dealer-applied software updates. System hard reset by pressing and holding the power button. Head unit replacement for persistent hardware failures.
Est. Cost: $0 (software update) - $3,000 (head unit)Transfer Case and Differential Fluid Leaks
The full-time 4WD system's transfer case and front/rear differentials develop seal leaks over time, leaving fluid spots and potentially allowing fluid levels to drop to damaging levels.
Replace the leaking seals on the transfer case and differentials. Refill with correct Mercedes-Benz specification lubricant. Regular fluid level checks at every service interval are recommended.
Est. Cost: $500 - $1,500Door Locking Mechanism Malfunctions
The electronically controlled door locks and latches intermittently fail to lock or unlock, produce grinding noises during operation, or trigger door-ajar warnings when properly closed. The heavy doors put extra stress on the mechanisms.
Replace the door lock actuator and latch assembly on the affected door. Software reset of the door control module. The G-Class door mechanisms are reinforced but the electronics remain a weak point.
Est. Cost: $400 - $1,200 per door