2019 Toyota Tundra: Transmission & Axle Gear Ratios

Transmission Gear Ratios

The 2019 Toyota Tundra comes equipped with a single transmission option, the robust Aisin AC60F 6-speed electronically controlled automatic transmission. This transmission is paired with both the 4.6L and 5.7L i-FORCE V8 engines.

Here are the gear ratios for the 6-speed automatic:

Available Axle Ratios

Toyota offered several different axle ratios for the 2019 Tundra, depending on the engine, trim level, and optional packages. The final drive ratio has a significant impact on the truck's performance, affecting both its towing capacity and fuel efficiency.

Note: The axle code can be found on the driver's side door jamb sticker.

How to Identify Your Axle Ratio

Knowing your truck's specific axle ratio is crucial for ordering the correct parts for maintenance or repairs, or for understanding its towing capabilities. Here’s how you can find it:

• Driver's Door Jamb Sticker: This is the most reliable method. Open the driver's side door and locate the large white and black sticker on the B-pillar. Look for the "A/TM" or "AXLE" code. For the 2019 Tundra, you will see a code like "A04A". The "A" signifies the rear axle housing size, and the "04A" corresponds to the 4.300 ratio.

• VIN Decoder: Several online VIN decoder services can provide detailed information about your Tundra's original factory specifications, including the axle ratio. Be aware that some services may be more accurate than others.

• Axle Tag (Less Common on Toyota): While more common on domestic trucks, some Toyotas may have a small metal tag bolted to the differential cover. This tag is stamped with the ring gear and pinion tooth count, which can be used to calculate the ratio (e.g., "43 10" would mean 43 divided by 10 = 4.30).

Towing vs. MPG Impact

The axle ratio plays a direct role in the trade-off between raw towing power and fuel economy.

• Numerically Higher Ratios (e.g., 4.300): A "taller" or "shorter" gear ratio like 4.300 provides more torque to the wheels at a given speed. This makes it easier for the engine to get a heavy load moving and maintain speed, especially on inclines. The engine will rev higher at highway speeds, which increases towing performance but consumes more fuel. This is why the powerful 5.7L Tundra models, especially those with the Tow Package, are equipped with the 4.300 ratio.

• Numerically Lower Ratios (e.g., 4.100): A "shorter" or "taller" gear ratio like 4.100 means the engine doesn't have to work as hard to maintain cruising speed. At a given speed, the engine RPM will be lower compared to a truck with a 4.300 ratio. This results in better fuel economy on the highway but offers less mechanical advantage for towing heavy loads. It provides a more balanced performance for daily driving and light-duty tasks.

Common Issues

The Toyota Tundra is renowned for its durability, and its driveline is no exception. While widespread, systemic issues are uncommon, like any mechanical component, they can experience wear over time, especially under heavy use.

• Carrier Bearing Wear: The driveshaft carrier bearing, which supports the multi-piece driveshaft, can sometimes wear out, leading to a noticeable vibration or a "whirring" noise at certain speeds. This is more common on trucks that are lifted or used for heavy towing.

• Pinion and Differential Bearings: Though rare on well-maintained Tundras, pinion or differential carrier bearings can fail. Symptoms include a persistent whining or howling noise that changes pitch with vehicle speed (not engine RPM). The noise may be more pronounced during acceleration or deceleration.

• Limited-Slip Clutch Wear: On models equipped with a limited-slip differential (LSD), the internal clutch packs can wear out over time, reducing their effectiveness. This might be noticed as a loss of traction in low-grip situations where both wheels should be providing power.

Regularly changing the differential fluid according to Toyota's recommended service intervals is the single most important step in ensuring a long, trouble-free life for your Tundra's axle and differential.

Find a driveline shop on Repairius.