2017 Subaru Forester Transmission & Axle Gear Ratios

This guide details the transmission and axle gear ratios for the 2017 Subaru Forester, providing crucial information for owners and technicians.

Transmission gear ratios

The 2017 Subaru Forester was offered with two transmission options: a 6-speed manual transmission (6MT) and a Lineartronic Continuously Variable Transmission (CVT).

6-Speed Manual Transmission

Lineartronic CVT

Available axle ratios

The final drive ratio (axle ratio) is critical for determining the overall gearing of the vehicle. For the 2017 Forester, all models, regardless of transmission, utilized the same final drive ratio.

How to identify your axle ratio

Unlike many manufacturers that use RPO codes on door jamb stickers, Subaru typically integrates the final drive ratio with the transmission assembly. To definitively identify your exact axle ratio, check the "Vehicle Information" sticker, usually located under the hood or on the driver's side door jamb. This sticker will list the transmission type and often the final drive ratio directly. For more detailed information, consult the owner's manual or a Subaru dealership using your VIN.

Towing vs MPG impact

The axle ratio plays a significant role in balancing towing capability and fuel economy. A numerically lower axle ratio (e.g., 3.08) means the engine will operate at lower RPMs at a given road speed, leading to better fuel economy. However, this comes at the cost of reduced torque multiplication at the wheels, which negatively impacts towing capacity and acceleration. Conversely, a numerically higher axle ratio (e.g., 4.10) results in the engine operating at higher RPMs, providing better towing performance and quicker acceleration due to increased torque multiplication. The trade-off is typically lower fuel economy.

The 2017 Subaru Forester uses a 4.444 axle ratio across all models. This ratio is a balanced choice, providing a good blend of everyday drivability, adequate towing capacity for its class, and reasonable fuel efficiency.

Common issues

While the Subaru Forester is known for its reliability, like any mechanical component, the driveline can experience wear over time. Common issues that can arise include:

• Ring & pinion whine: This is often heard as a howling or whirring noise that changes with vehicle speed and load. It can indicate wear in the ring and pinion gears or improper mesh, often due to incorrect setup or bearing wear.
• Carrier bearing wear: The carrier bearings support the differential carrier. Worn bearings can lead to noise (often a rumble or growl) and potentially excessive play in the differential, impacting gear mesh.
• Limited-slip clutch wear (if applicable): While not all Foresters are equipped with a mechanical limited-slip differential, those that are might experience wear in the clutch packs over time. This can result in a loss of limited-slip function, manifested as a single wheel spinning on slippery surfaces or chatter during turns. The 2017 Forester typically uses an electronically controlled multi-plate transfer clutch for torque distribution, which can also experience wear if not properly maintained.

Regular differential fluid changes as recommended by Subaru are crucial for extending the life of these components.

Find a driveline shop on Repairius.