Axle S172 Dana.

The axle is crafted for 4×2, 6×2, and 8×2 applications up to 25,000 lbs. (11,340 kg) GAWR. It offers a broad range of gear ratios, from 3.07 to 6.14, and features a low hypoid offset with High-Power Density™ AdvanTEK® gearing to drive maximum efficiency. The high-strength pinion bearings allow for greater lifespan under heavy loads, improving durability and overall performance. In addition, a passive lube management system requires less lube while utilizing a patented meter to optimize the amount of lube flow to the high-efficiency bearings.
The single drive axle can also be paired with the Dana tag axle as part of the Spicer® EconoTrek™ tandem axle, a durable, lightweight 6×2 configuration that offers increased fuel economy, improved performance, and reduced maintenance for heavy-duty linehaul tractors. This system is up to 3 percent more efficient and up to 380 pounds lighter than typical 6×4 offerings.