2016 GMC Acadia Transmission & Axle Gear Ratios

Transmission gear ratios

The 2016 GMC Acadia was primarily equipped with a 6-speed automatic transmission. All trims, including the SLE, SLT, and Denali, utilized this transmission, whether in front-wheel drive (FWD) or all-wheel drive (AWD) configurations. This transmission provided a good balance of performance and fuel economy for the Acadia's target market.

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

Available axle ratios

The 2016 GMC Acadia offered a limited number of axle ratios, primarily dictated by its FWD or AWD drivetrain configuration. The most common ratio available was designed to provide a good balance for everyday driving, including adequate towing for a mid-size SUV and respectable fuel economy.

How to identify your axle ratio

Identifying the axle ratio on your 2016 GMC Acadia is relatively straightforward. The easiest method is to check the RPO (Regular Production Option) sticker. This sticker is typically found on the inside of the glove box door or on the driver's side door jamb. Look for a three-digit alphanumeric code. For the 2016 Acadia, the most common code will be "GH2", which corresponds to the 3.16:1 axle ratio. Unlike some heavier-duty trucks, the Acadia typically doesn't have an axle tag directly on the differential housing.

If you are unable to locate the RPO sticker, a VIN decoder service can sometimes provide this information by breaking down the vehicle's factory options.

Towing vs MPG impact

For the 2016 GMC Acadia, with its single widely available axle ratio of 3.16:1, there isn't a direct choice to make between maximizing towing capacity or fuel economy through different axle ratios. However, understanding the general principle is important.

Generally, a numerically lower axle ratio (e.g., 3.16:1 vs. hypothetically a 3.73:1) means that the engine will operate at lower RPMs for a given road speed. This typically translates to better fuel economy on the highway because the engine is not working as hard. The trade-off is often reduced towing capacity and slower acceleration from a standstill, as the engine provides less mechanical advantage to the wheels.

Conversely, a numerically higher axle ratio (ee.g., 3.73:1 versus 3.16:1) means the engine will rev higher at the same road speed. This provides more torque to the wheels, leading to improved acceleration and greater towing capability. The downside is usually a decrease in fuel economy, especially at highway speeds. The 3.16:1 ratio in the Acadia was chosen by GMC to provide a good compromise for most owners, offering reasonable towing for an SUV of its class while maintaining respectable fuel efficiency.

Common issues

The 2016 GMC Acadia's drivetrain, including its transmission and differential, is generally robust. However, as with any vehicle component, some issues can arise over time.

• Ring & Pinion Whine: This is a common symptom of wear in the differential. A persistent humming or whining sound that changes with vehicle speed, especially when decelerating or under light load, can indicate worn ring and pinion gears or improper mesh. This often necessitates differential overhaul or replacement.

• Carrier Bearing Wear: The carrier bearings support the differential carrier within the axle housing. If these bearings wear out, they can produce a growling or rumbling sound that may increase with speed. Early detection and replacement can prevent more extensive damage.

• Limited-Slip Clutch Wear (AWD models): While not as common in the Acadia's FWD-biased AWD system as in dedicated limited-slip differentials, components within the power transfer unit (PTU) or rear differential (in AWD models) can experience wear. Symptoms might include shuddering or binding during turns, indicating issues with clutch packs or fluid. Regular fluid changes are crucial for the longevity of these components.

Find a driveline shop on Repairius.