2014 Toyota Tundra: Transmission & Axle Gear Ratios

Transmission Gear Ratios

The 2014 Toyota Tundra was offered with two excellent automatic transmissions, a 5-speed for the V6 and a 6-speed for the V8s. The 6-speed automatic (AB60E/F) is known for its durability and smooth shifts, making it a popular choice for truck owners who tow, while the 5-speed provides a reliable and efficient option for the V6 models.

6-Speed Automatic (AB60E/F) — 4.6L & 5.7L V8

5-Speed Automatic (A750E/F) — 4.0L V6

Available Axle Ratios

The axle ratio is the final link in your Tundra's powertrain, multiplying the torque delivered by the transmission one last time before it reaches the rear wheels. Toyota offered several ratios for 2014, each tailored to a specific purpose, whether it be maximizing fuel economy, enhancing towing capability, or providing a balanced blend of both.

How to Identify Your Axle Ratio

Knowing your Tundra's specific axle ratio is crucial when ordering parts or diagnosing driveline issues. Toyota makes this information relatively easy to find.

1. Driver's Door Jamb Sticker: The most reliable method is to check the certification label on the driver's side door jamb. Look for the "A/TM" (Axle/Transmission) code. The axle code is a four-character code starting with a letter. The table above lists the common codes for the 2014 model year.
2. VIN Decoder: Several online VIN decoders can provide a build sheet for your truck, which often includes the factory-installed axle ratio.
3. Axle Tag (Less Common on Toyota): While more common on domestic trucks, some Toyotas may have a small metal tag bolted to the differential housing that specifies the ratio (e.g., "4.30").

Towing vs. MPG Impact

The axle ratio has a direct and significant impact on both your Tundra's towing capacity and its fuel efficiency. The relationship is a classic trade-off:

• Numerically Higher Ratios (e.g., 4.30): These are often called "shorter" gears. They multiply engine torque more aggressively, making it easier to get a heavy load moving from a standstill. This is ideal for towing trailers, boats, or heavy equipment. The downside is that the engine must run at a higher RPM at highway speeds, which increases fuel consumption.

• Numerically Lower Ratios (e.g., 3.90): These are known as "taller" gears. They don't multiply torque as much, requiring the engine to work a bit harder off the line. However, they allow the engine to turn at a much lower RPM when cruising at highway speeds. This results in better fuel economy and a quieter ride, making it the preferred choice for drivers who primarily use their truck for commuting or long-distance travel without a trailer.

Choosing the right ratio depends entirely on your needs. For a dedicated tow vehicle, the 4.30 ratio is unmatched. For a daily driver that occasionally hauls, the 4.10 or 3.90 offers a more balanced experience.

Common Issues

The 2014 Tundra's driveline is robust and generally considered very reliable. However, like any mechanical system, some issues can arise, especially under heavy use or with high mileage.

• Ring & Pinion Gear Whine: A howling or whining noise from the rear differential that changes pitch with vehicle speed can indicate worn ring and pinion gears. This is often caused by fluid breakdown, overloading, or improper gear setup after a repair.
• Carrier Bearing Failure: The carrier bearings support the differential carrier within the axle housing. Failure can cause a rumbling or growling noise that is most noticeable when turning. It's critical to address this issue promptly to avoid further damage to internal components.
• Limited-Slip Differential (LSD) Wear: If your Tundra is equipped with an LSD, the internal clutch packs can wear out over time. This may present as a chattering or groaning sound during tight, low-speed turns. Using the correct gear oil with a friction modifier additive is essential for LSD longevity.

Regular differential fluid changes with high-quality gear oil are the best preventative maintenance you can perform to ensure a long and trouble-free service life for your Tundra's axles.

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