Faced with strict emissions targets, downsizing demands, new high-torque turbocharged engines and electric-drive systems, an increasing number of vehicle manufacturers are making use of GKN’s patented face-spline technology to connect sideshaft joints to a vehicle’s wheel hubs, according to Frank Huerter, the company’s automotive aftermarket commercial director. 

Features and benefits of the GKN face spline include:

• Is considerably less complex, as well as lighter and more compact than previous designs;

• Has a greater surface area than longitudinal shafts, which allows for torque transmission up to 50 percent greater than previously possible;

• Offers a zero-play connection to the wheel hub, simplifies assembly and is easier to maintain, and 

• Has a new, space-saving membrane boot that enables articulation up to 25 degrees.

In the past, sideshafts usually were connected to a vehicle’s wheel hub with a splined longitudinal shaft. GKN has replaced the more traditional longitudinal spline with a spline on the face of the joint itself, hence the name – face spline. The spline on the face joint connects with a second spline on the wheel hub. A fixing bolt secures and connects the two parts.

GKN’s lighter, less complex face-spline design makes it particularly well suited for future powertrains. Weight savings at the wheel also noticeably improves ride characteristics by reducing unsprung mass by up to 20 percent. 

In addition, GKN Automotive’s ST technology (twin ball sideshaft with s-shaped ball track) lowers the joint’s internal friction and contributes to even further improvements in fuel economy.

The sideshaft itself offers further potential for improved efficiency. GKN, for example, combines the face-spline joint with a hollow monoblock shaft that delivers exceptional stability and torsional stiffness with minimal weight to provide additional ride and fuel-economy benefits. 

Huerter notes that performance improvements achieved by systems combining a face-spline joint with a monoblock hollow shaft have been so significant that many major automakers have opted to use this GKN Automotive technology almost exclusively, especially in their all-wheel-drive models.

“The growing use of our face-spline and monoblock technologies in OEM applications also promises increased sales for our aftermarket business,” Huerter says. “As the developer, we now can offer our face-spline products to the replacement parts market with absolutely no compromise in design or quality.

“That means independent garages and repair shops can service and maintain the latest new-model vehicles while profiting from our efficient, high-quality driveline components.”

More information can be found at gknautomotive.com/en/AftermarketMotorsport.