2020 Toyota Tundra Transmission & Axle Gear Ratios

The 2020 Toyota Tundra is a robust and capable full-size pickup truck, known for its strong V8 engine and reliable performance. Understanding its transmission and axle gear ratios is crucial for optimizing its capabilities, whether for towing, off-roading, or daily driving.

Transmission gear ratios

For 2020, the Toyota Tundra utilized a single transmission option across all trims: the Aisin AC60F 6-speed automatic transmission.

Available axle ratios

The 2020 Tundra offered a few axle ratio options, primarily depending on the drivetrain and trim level. The most common ratio is 4.30 across the board.

How to identify your axle ratio

Identifying your Tundra's axle ratio is straightforward. On Toyota vehicles, you'll typically find the axle code on the sticker located on the driver's side door jamb. Look for the "Axle" code, which will be a series of letters and numbers (e.g., A01A or A01B). While this code primarily identifies the differential type and whether it's 2WD or 4WD, for the 2020 Tundra, the 4.30 ratio was standard. For more specific identification, a VIN decoder can provide precise details based on your vehicle's manufacturing information.

Towing vs MPG impact

Axle ratios play a significant role in how your truck performs, particularly concerning towing and fuel economy. A numerically higher axle ratio (like the 4.30 found in the Tundra) means the engine will turn more revolutions per minute (RPM) for a given road speed. This provides more torque to the wheels, which is beneficial for heavy towing and hauling, allowing the truck to accelerate more easily and maintain speed under load.

Conversely, a numerically lower axle ratio would result in lower engine RPM at cruising speeds, potentially leading to better fuel economy. However, the 2020 Tundra's 4.30 ratio is a balanced choice, providing a good compromise between towing capability and everyday drivability, though it won't offer the absolute highest MPG figures due to its design for robust performance.

Common issues

While the Tundra is known for its reliability, some general drivetrain components can experience wear over time:

• Ring & Pinion Whine: A high-pitched whine that increases with vehicle speed can indicate wear or improper setup of the differential's ring and pinion gears. This often becomes more noticeable during acceleration or deceleration.
• Carrier Bearing Wear: The carrier bearings support the differential carrier within the axle housing. Wear in these bearings can lead to humming or rumbling noises, especially at certain speeds.
• Limited-Slip Clutch Wear: If your Tundra is equipped with a limited-slip differential, the clutch packs can wear out over time, leading to a loss of the limited-slip function. This might manifest as uneven power delivery to the wheels in low-traction situations.

These issues are not exclusive to the Tundra but are common to many trucks with high mileage or those subjected to frequent heavy loads and towing.

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