2016 Ram 2500: Transmission & Axle Gear Ratios

Transmission Gear Ratios

66RFE 6-Speed Automatic (Gas)

68RFE 6-Speed Automatic (Diesel)

G56 6-Speed Manual (Diesel)

Available Axle Ratios

How to Identify Your Axle Ratio

For Ram trucks, the axle ratio information is typically found on a sticker in the glove box. Look for terms like "Anti-Spin Differential" and a specific ratio number (e.g., 3.73, 4.10). You can also use a VIN decoder service, which will provide a build sheet with the original factory equipment, including the axle ratio. Unlike Ford or GM, a tag on the differential cover or a door-jamb sticker is less common for identifying the ratio on Ram trucks.

Towing vs. MPG Impact

The axle ratio has a direct and significant impact on both your truck's towing capacity and its fuel economy. A "shorter" or numerically higher ratio (like 4.10) multiplies engine torque more effectively, resulting in better off-the-line acceleration and increased towing performance. However, this comes at the cost of higher engine RPM at highway speeds, which reduces fuel efficiency.

Conversely, a "taller" or numerically lower ratio (like 3.42) results in lower engine RPM on the highway, which is better for fuel economy. The trade-off is reduced towing capacity and a less responsive feel when accelerating from a stop, especially with a heavy load.

Common Issues

While the AAM axles used in the 2016 Ram 2500 are generally robust, some issues can arise, particularly under heavy use. The ring and pinion gears can develop a whine over time due to wear, which might indicate a need for backlash adjustment or gear replacement. Carrier bearing failure is another potential problem, often manifesting as a rumbling or grinding noise. On models equipped with a limited-slip differential, the clutch packs can wear out, leading to reduced traction in low-grip situations.

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