2019 Ram 1500: Transmission & Axle Gear Ratios

Transmission Gear Ratios

The 2019 Ram 1500 comes exclusively with the TorqueFlite 8-speed automatic transmission, a versatile and efficient unit manufactured by ZF (850RE/8HP75). The gear ratios are the same regardless of whether it is paired with the 3.6L V6 or the 5.7L HEMI V8.

Available Axle Ratios

The axle ratio is the final link in the powertrain, multiplying the torque delivered by the transmission before it reaches the wheels. For 2019, the Ram 1500 offered several axle ratios tailored for different needs, from maximizing fuel economy to enabling incredible towing performance.

How to Identify Your Axle Ratio

Knowing your specific axle ratio is crucial for ordering repair parts or understanding your truck's capabilities. There are a few ways to find this information:

• VIN Decoder: The easiest method is to use an online VIN decoder. The VIN contains codes that specify how the truck was equipped from the factory, including the axle type and ratio.
• Axle Differential Tag: Look for a small metal tag bolted to the differential housing (the "pumpkin" in the middle of the rear axle). This tag has codes stamped into it. Look for the set of numbers that resembles a ratio, such as "3 21" (for 3.21) or "3 92" (for 3.92).
• Build Sheet/Window Sticker: If you have the original window sticker or can get a build sheet from a Ram dealer using your VIN, it will explicitly list the "Axle Ratio" as a line item.

Unlike GM vehicles, Ram does not place an RPO code sticker in the door jamb or glove box with this information.

Towing vs. MPG Impact

The relationship between axle ratios, towing, and fuel economy is a game of trade-offs. The ratio number itself refers to how many times the driveshaft must turn to spin the axles (and thus the wheels) one full rotation.

• Numerically Lower Ratios (e.g., 3.21): These are often called "taller" gears. The engine turns at a lower RPM at highway speeds. This is ideal for fuel economy, as the engine is under less strain during cruising. However, it provides less torque multiplication, meaning it has to work harder to get a heavy load moving from a stop, resulting in lower towing capacity.
• Numerically Higher Ratios (e.g., 3.92): These are known as "shorter" gears. They provide significant torque multiplication, making it much easier to pull heavy trailers and get off the line quickly. This is why the 3.92 ratio is essential for achieving the Ram 1500's maximum tow rating. The trade-off is that the engine runs at a higher RPM at highway speeds, which increases fuel consumption.

The 3.55 ratio offers a compromise between the two extremes, providing a good balance of towing capability and reasonable fuel economy for daily driving.

Common Issues

The driveline in the 2019 Ram 1500 is generally robust, but like any mechanical system, it can have issues. Some owners have reported:

• Ring & Pinion Gear Whine: A howling or whining noise that changes with vehicle speed (not engine RPM) can indicate a problem with the gear set alignment or wear within the differential. This often requires professional inspection and adjustment.
• Rear Differential Bearing Failure: A rumbling or grinding noise from the rear of the truck, particularly noticeable when turning, could be a sign of a failing carrier or pinion bearing.
• eLocker Issues: For models equipped with the electronic locking differential (often paired with the 3.92 axle), failure of the electronic actuator can prevent the differential from locking when needed for traction.

Addressing driveline issues promptly is critical to prevent more extensive and costly damage.

If you're experiencing noise or vibration from your truck's axles, it's time to consult a professional. Find a driveline shop on Repairius.