NAG1 Transmission

Specifications

The NAG1 transmission is a longitudinal 5-speed automatic transmission originally engineered by Mercedes-Benz and widely adopted by Chrysler, Dodge, and Jeep in many rear-wheel-drive and all-wheel-drive vehicles. Introduced in the mid-1990s, it uses a hydraulic torque converter with an electronically controlled lock-up clutch, three planetary gear sets, and multiple multi-plate clutches and brakes to provide five forward speeds and one reverse. The transmission is managed by an electronic transmission control module (TCM) that monitors inputs such as throttle position, engine speed, and vehicle speed to control shift timing and pressure.

It incorporates adaptive shift technology, allowing the system to learn the driver’s style and adjust shift points for smoother operation and improved durability. Typical gear ratios are 3.59:1 (1st), 2.19:1 (2nd), 1.41:1 (3rd), 1.00:1 (4th), and 0.83:1 (5th overdrive) with reverse around 3.16:1, helping provide both strong launch performance and reduced engine speed during highway driving. 

The NAG1 also includes manual shift capability, an integrated oil pump for hydraulic pressure, and ATF+4 transmission fluid compatibility for lubrication, cooling, and hydraulic control. Known for its high torque capacity (up to roughly 580 Nm depending on version), robust internal construction, and reliability, the NAG1 was widely used from the late 1990s to early 2010s in luxury sedans, SUVs, and performance vehicles before newer multi-speed transmissions replaced it.

Transmission Variants

W5A280

The W5A280 is the light-duty version of the NAG1 transmission designed for lower torque applications. It is commonly used in commercial vans and smaller passenger vehicles such as the Mercedes-Benz Vito and Mercedes-Benz Sprinter. This variant is optimized for fuel efficiency and durability in light-load conditions, making it suitable for vehicles with smaller engines and moderate power output.

W5A300 / W5A330

The W5A300 and W5A330 variants are medium-duty versions used in a wide range of passenger cars and SUVs equipped with 4-, 5ll, or 6-cylinder engines. These transmissions provide a balance between performance and efficiency and were commonly installed in several Mercedes-Benz passenger vehicles as well as models from Chrysler, Dodge, and Jeep. They offer reliable operation for everyday driving and moderate towing demands.

W5A400

The W5A400 is a heavier-duty version designed for vehicles with higher torque outputs, particularly SUVs equipped with V8 engines. It features strengthened internal components to handle greater loads and towing requirements. This variant was used in several larger luxury SUVs produced by Mercedes-Benz and related platforms.

W5A580 (WA580)

The W5A580 is the most widely used NAG1 variant in North American vehicles from Chrysler, Dodge, and Jeep. It is designed for high-torque engines such as HEMI V8s and can handle around 580 Nm of torque. This transmission was used in vehicles like the Jeep Grand Cherokee and Jeep Wrangler, providing strong durability for performance driving and towing.

W5A900

The W5A900 is the highest-capacity variant of the NAG1 family. It was developed for very high-output luxury and performance vehicles with powerful V8 and V12 engines from Mercedes-Benz. With significantly strengthened internal components and higher torque tolerance, it was used in flagship models where smooth power delivery and reliability under extreme loads were required.

Frequently Asked Questions