Partial on Deceleration and Full on Acceleration – Difference between a 1.5-Way and a 2-Way Diff , Well here in my hand I have a 1.5-Way , now if you notice here's where the difference is , it's on this cutout , one side is a diamond shape the other side's got a larger radius so we have a sharp angle and a very smooth angle , now what happens is under acceleration when a diff moves like this this pinion shaft actually pushes against the differential and will spread out greatly , now under deceleration the opposite happens however since we have a larger groove it doesn't spread it out as much and that's where you only get partial on deceleration and full on acceleration