Peter Banks If you are a Subaru owner, you may have heard of the term "viscous coupling" thrown around. But what exactly is it, and how does it work? In this article, we will take a deep dive into the world of Subaru viscous coupling, explaining what it is, how it works, and why it’s important.
Key Takeaways
- Viscous coupling is a type of limited-slip differential that transfers torque between the front and rear wheels of a vehicle.
- Subaru uses a center differential with a viscous coupling on their Symmetrical All-Wheel Drive system.
- The viscous coupling uses a thick fluid to transfer torque between the front and rear wheels, sending more power to the wheels with more traction.
- The benefits of Subaru viscous coupling include improved traction, better handling, and increased safety on slippery roads.
What Is Viscous Coupling?
Viscous coupling is a type of limited-slip differential that can transfer torque between the two axles of a vehicle. In a traditional differential, torque is split equally between the front and rear wheels, regardless of whether one set of wheels has better traction than the other. This can cause wheel slip and reduced traction, especially in slippery or uneven conditions.
Viscous coupling works by using a thick fluid to transfer torque between the two axles. The fluid is located in a sealed housing that is connected to both the front and rear axles through a series of gears. When one set of wheels loses traction, the fluid heats up and becomes more viscous, transferring more torque to the wheels with better traction.
How Does Subaru Viscous Coupling Work?
Subaru uses a type of viscous coupling on their Symmetrical All-Wheel Drive system. The system consists of a center differential that is located in the transmission and is connected to both the front and rear axles. The center differential is responsible for splitting torque between the front and rear wheels, while the viscous coupling is responsible for transferring torque between the two axles.
The viscous coupling in a Subaru is located in a housing that is filled with a thick silicone fluid. The housing is connected to both the front and rear axles through a series of gears. When the vehicle is driving straight, the silicone fluid is evenly distributed throughout the housing, and torque is split equally between the front and rear axles.
However, when one set of wheels loses traction, the silicone fluid heats up and becomes more viscous. This causes the gears to spin at different speeds, which in turn causes the torque to be transferred to the wheels with better traction. This process happens almost instantly, allowing the vehicle to maintain traction and stability in slippery or uneven conditions.
Benefits of Subaru Viscous Coupling
There are several benefits to using a viscous coupling on a Subaru vehicle.
Improved Traction
By transferring torque between the front and rear axles, a viscous coupling can help improve traction in slippery or uneven conditions. This can be especially useful in areas with snow, ice, or rain, where maintaining traction is crucial for safe driving.
Better Handling
Because a viscous coupling can transfer torque to the wheels with better traction, it can also improve handling and stability. This can be especially important for drivers who enjoy taking their Subaru off-road or on winding roads with sharp turns.
Increased Safety
Ultimately, the main benefit of Subaru viscous coupling is increased safety. By improving traction and handling, a viscous coupling can help drivers maintain control of their vehicle in a variety of driving conditions. This can reduce the risk of accidents and ensure that drivers and passengers arrive at their destination safely.
Frequently Asked Questions
What Subaru models have viscous coupling?
Subaru uses viscous coupling on their Symmetrical All-Wheel Drive system, which is available on most of their models.
How often should I service my Subaru viscous coupling?
Subaru recommends servicing the viscous coupling every 30,000 miles or three years, whichever comes first.
Can I replace the viscous coupling myself?
While it is possible to replace the viscous coupling yourself, it is recommended that you have it done by a professional mechanic. This is because the process can be complex and requires specialized tools and knowledge.
Conclusion
Subaru viscous coupling is an important part of the Symmetrical All-Wheel Drive system. By transferring torque between the front and rear axles, a viscous coupling can help improve traction, handling, and safety in a variety of driving conditions. If you own a Subaru, it’s important to understand how your viscous coupling works and how to take care of it to ensure that your vehicle remains safe and reliable.
