The NAG1 transmission, also known as the W5A580, is a 5-speed automatic transmission widely used in Chrysler, Dodge, Jeep, and Mercedes-Benz vehicles from the early 2000s through the mid-2010s. While this transmission is known for durability, the correct transmission fluid level and type are absolutely critical for proper operation and longevity.
NAG1 Transmission Fluid Level Chart
| Transmission Fluid Temperature | Fluid Level Range (mm) |
|---|---|
| 68°F (20°C) | 46 – 56 mm |
| 86°F (30°C) | 52 – 62 mm |
| 104°F (40°C) | 59 – 69 mm |
| 122°F (50°C) | 66 – 76 mm |
| 140°F (60°C) | 73 – 83 mm |
| 158°F (70°C) | 80 – 90 mm |
| 176°F (80°C) | 87 – 97 mm |
Important Notes:
- Measurements are taken using a service dipstick tool
- Fluid temperature must be verified using a scan tool
- Do not guess fluid temperature
Related Transmission Fluid Temperature Chart(Complete Guide)
What Is the NAG1 Transmission?
The NAG1 is a fully electronic, 5-speed automatic transmission originally designed by Mercedes-Benz and later adapted by Chrysler. It features adaptive shifting, lock-up torque converter technology, and a sealed system design.
Common vehicles equipped with the NAG1 transmission include:
- Dodge Charger, Magnum, Challenger
- Chrysler 300
- Jeep Grand Cherokee, Commander
- Dodge Ram 1500 (select years)
- Mercedes-Benz C-Class, E-Class, ML-Class (with variations)
Because the transmission is electronically controlled and temperature-sensitive, fluid level accuracy is more important than on older designs.
Why Proper Fluid Level Matters
Maintaining the correct fluid level in a NAG1 transmission is essential for several reasons:
- Ensures proper hydraulic pressure
- Prevents clutch slippage
- Reduces internal heat buildup
- Protects the valve body and solenoids
- Extends transmission service life
Both overfilling and underfilling can cause drivability issues such as harsh shifting, delayed engagement, overheating, or even internal damage.
Related Transmission Fluid Dipstick Level(Complete Guide)
NAG1 Transmission Fluid Type
The NAG1 transmission requires a specific fluid and is not compatible with standard Dexron or Mercon fluids.
Approved transmission fluids:
- ATF+4 (Chrysler specification)
- Mercedes-Benz 236.10 / 236.12 / 236.14 (depending on model year)
Using the wrong fluid can result in poor shift quality and long-term transmission failure.
Related Transmission Fluid Level Chart(For All Types)
How to Check NAG1 Transmission Fluid Level
Although there is no factory dipstick, checking the fluid level is straightforward with the correct tools.
Basic Steps:
- Park the vehicle on level ground
- Start the engine and allow the transmission to reach the target temperature
- Apply the parking brake
- Shift through all gears, then leave in Park
- Insert the NAG1 service dipstick into the fill tube
- Read fluid level based on current temperature
- Adjust fluid as needed
Adding fluid is done through the same fill tube using a funnel designed for sealed transmissions.
Common Symptoms of Incorrect Fluid Level
If the NAG1 transmission fluid level is incorrect, you may notice:
- Delayed shifting or gear engagement
- Hard or erratic shifts
- Transmission overheating
- Slipping under acceleration
- Limp mode activation
- Transmission fault codes
Ignoring these symptoms can lead to expensive repairs.
Related 2014 Chrysler Town and Country Transmission Fluid Level Chart
NAG1 Transmission Fluid Capacity
Fluid capacity depends on service type:
| Service Type | Approximate Capacity |
|---|---|
| Drain and refill | 5 – 6 quarts |
| Pan & filter service | 6 – 7 quarts |
| Complete dry fill | 8 – 9 quarts |
Always add fluid gradually and recheck levels using the temperature chart.
FAQs
What transmission fluid does a NAG1 use?
The NAG1 transmission requires ATF+4 for Chrysler, Dodge, and Jeep applications, while Mercedes-Benz versions use fluids meeting MB 236.10, 236.12, or 236.14 specifications; standard Dexron or Mercon fluids should never be used because they can cause poor shift quality, overheating, and internal transmission damage.
What is the correct level of transmission fluid?
The correct NAG1 transmission fluid level depends on fluid temperature, not engine temperature, and is measured using a service dipstick in millimeters; for example, at 104°F (40°C), the proper level is 59–69 mm, and the reading must be taken with the engine running, the vehicle level, and the transmission warmed to the specified temperature.
How much transmission fluid does a Jeep XJ take?
A Jeep XJ typically holds 8–9 quarts of automatic transmission fluid for a complete dry fill, while a standard drain and refill usually requires 4–5 quarts, depending on whether the torque converter is drained and the transmission type installed.
What’s the normal range for transmission fluid?
The normal operating range for NAG1 transmission fluid is generally between 122°F and 176°F (50°C–80°C), where fluid level readings fall between 66 mm and 97 mm, ensuring proper lubrication, hydraulic pressure, and cooling during normal driving conditions.
How many speeds is a NAG1 transmission?
The NAG1 is a 5-speed automatic transmission, featuring electronically controlled shifting, adaptive learning, and a lock-up torque converter designed for smooth performance and improved fuel efficiency.
How much HP can NAG1 handle?
In stock form, the NAG1 transmission can reliably handle approximately 400–450 horsepower, and with upgraded internals, valve body modifications, and improved cooling, it has been proven to support 600 horsepower or more in performance applications.
Final Thoughts
The NAG1 transmission fluid level chart is an essential reference for anyone servicing or maintaining this popular automatic transmission. Because the system is temperature-sensitive and sealed, accuracy matters more than speed. Using the correct fluid, following proper procedures, and verifying fluid temperature will help ensure smooth shifting and long transmission life.
Whether you’re a DIY enthusiast or a professional technician, understanding how to correctly measure and adjust NAG1 transmission fluid can save you from costly mistakes and keep your vehicle performing at its best.
