2016 Ford F-250 Super Duty Transmission & Axle Gear Ratios

Transmission gear ratios

The 2016 Ford F-250 Super Duty was available with one primary transmission: the TorqShift 6-speed automatic.

TorqShift 6-speed Automatic (6R140)

Available axle ratios

The 2016 F-250 offered a range of axle ratios to suit various needs, from heavy-duty towing to more balanced performance. The availability often depended on the engine choice and trim level.

[Note]: "Electronic Locking" (E-Locker) differentials are often indicated by a different axle code suffix (e.g., "L" vs. "Blank" for non-limited slip).

How to identify your axle ratio

Identifying the correct axle ratio for your 2016 Ford F-250 Super Duty is crucial for proper maintenance and upgrades. There are a few reliable methods:

• Door-Jamb RPO Sticker: Open the driver's side door and locate the white or yellow sticker on the door jamb. Look for the "AXLE" code. This code will typically correspond to the ratio and differential type (e.g., "3L" for 3.55 electronic locking).
• Axle Tag: Many Ford truck axles have a metal tag attached to one of the differential cover bolts. This tag will often clearly display the axle ratio, such as "3.73." This is the most definitive method if the sticker is missing or unreadable.
• VIN Decoder: You can use your Vehicle Identification Number (VIN) to look up the original specifications of your truck, which will include the axle ratio. Many online VIN decoders can provide this information.

Towing vs MPG impact

Axle ratios have a direct and significant impact on both your truck's towing capability and its fuel economy.

• Numerically Lower Ratios (e.g., 3.31, 3.55): These ratios mean the driveshaft turns fewer times for each rotation of the wheel. This results in lower engine RPMs at highway speeds, leading to better fuel economy. However, with less mechanical advantage, the engine has to work harder to get a load moving, reducing towing capacity and acceleration.
• Numerically Higher Ratios (e.g., 3.73, 4.10, 4.30): These ratios cause the driveshaft to turn more times per wheel rotation. This provides greater mechanical leverage, making it easier for the engine to accelerate and tow heavy loads. The trade-off is higher engine RPMs at cruising speeds, which reduces fuel efficiency.

Choosing the right axle ratio is a balance. If you frequently tow heavy loads or drive in mountainous terrain, a higher ratio is generally more suitable. If your driving consists mostly of unladen highway cruising, a lower ratio will save you money at the pump.

Common issues

While the 2016 Ford F-250 Super Duty is known for its robust drivetrain, some common issues can arise with the rear axle and differential over time:

• Ring and Pinion Whine: A persistent whining noise, especially noticeable at certain speeds or under acceleration/deceleration, can indicate wear or improper setup of the ring and pinion gears. This often necessitates replacement of the gear set and proper shimming.
• Carrier Bearing Wear: The bearings that support the differential carrier can wear out, leading to humming or growling noises, particularly at varying speeds. If left unaddressed, this can lead to further damage.
• Limited-Slip Clutch Wear (if equipped): Ford's electronic locking differential generally avoids the traditional limited-slip clutch pack issues, but if your truck has an aftermarket or different type of limited-slip differential, wear in the clutch packs can lead to chattering or shuddering during turns as the differential struggles to differentiate wheel speeds.
• Pinion Seal Leaks: Leaks around the pinion seal are not uncommon and can lead to fluid loss, potentially causing premature wear if the fluid level drops too low. These should be addressed promptly.

Regular differential fluid changes with the correct type of fluid (often synthetic for these heavy-duty applications) are crucial for prolonging the life of your axle components.

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