2016 Ford F-350 Super Duty Transmission & Axle Gear Ratios

Transmission gear ratios

For the 2016 Ford F-350 Super Duty, the sole transmission option was the TorqShift 6-speed automatic transmission.

TorqShift 6-speed Automatic Transmission (6R140)

Available axle ratios

The 2016 Ford F-350 Super Duty offered a variety of axle ratios to suit different needs, from maximizing fuel economy to heavy-duty towing.

How to identify your axle ratio

Identifying your F-350 Super Duty's axle ratio is crucial for proper maintenance and understanding its capabilities. For Ford vehicles, the most reliable way to find this information is by checking the door-jamb sticker located on the driver's side door-frame. Look for the "AXLE" code. This code will correspond to one of the ratios listed in the table above. For example, a code of "3L" indicates a 3.31:1 ratio with a limited-slip differential, while a code of "L9" indicates a 3.73:1 ratio with a limited-slip differential. If the door jamb sticker is missing or illegible, you may also find an axle tag bolted to one of the differential cover bolts on the rear axle. This metal tag will often have the ratio stamped on it. Finally, a Ford dealership can typically provide this information using your vehicle's VIN.

Towing vs MPG impact

Axle ratios play a significant role in determining how your 2016 Ford F-350 Super Duty performs in terms of both towing capability and fuel economy.

• Numerically Lower Ratios (e.g., 3.31:1, 3.55:1): These ratios mean the engine turns fewer times for each rotation of the wheels. This results in better fuel economy on the highway as the engine operates at lower RPMs. However, it also translates to reduced towing capacity and slower acceleration, as the engine has to work harder to get the load moving.

• Numerically Higher Ratios (e.g., 4.10:1, 4.30:1): Conversely, higher ratios mean the engine turns more times for each rotation of the wheels. This provides superior towing power and quicker acceleration, making it ideal for hauling heavy loads or navigating challenging terrain. The trade-off is lower fuel economy, especially at highway speeds, due to the engine operating at higher RPMs.

• Balanced Ratios (e.g., 3.73:1): Many owners find a mid-range ratio like 3.73:1 offers a good compromise between towing capability and fuel efficiency, making it a versatile choice for a variety of uses.

Common issues

While the Ford F-350 Super Duty is a robust truck, some common issues can arise with the driveline components:

• Ring & Pinion Whine: A persistent whining noise that increases with vehicle speed can indicate wear on the ring and pinion gears within the differential. This is often due to improper gear setup, lack of lubrication, or heavy towing demanding more from the gears.
• Carrier Bearing Wear: The carrier bearings support the differential housing. Worn carrier bearings can produce a growling or howling sound, especially during acceleration or deceleration. If left unaddressed, this can lead to more significant damage to the differential.
• Limited-Slip Clutch Pack Wear: For vehicles equipped with a limited-slip differential, the clutch packs can wear out over time. Symptoms often include chattering or shuddering during tight turns as the clutches struggle to engage smoothly. Regular differential fluid changes with the correct friction modifier are essential for maximizing the life of these components.

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