Dana's Spicer ring and pinion gear options for Dana 44 (226 mm) and Dana 60 (248mm) rear axles include additional ratios. The ratios, 4.56, 4.88, and 5.13, add to existing ratios of the Dana 60 axle that range from 3.54 to 7.17 and the Dana 44 axle that range from 3.07 to 5.13. The components come heat treated to ensure the optimal hardness of the steel used. During manufacturing, face hobbing was used to accurately cut the gears to achieve desired spacing between gear teeth. This reduces noise, vibration and harshness, ensuring a quieter ride.