For Jeep Wrangler JK 2018 All Engine 3.21 Front Axle Ratio, Dana 30 only. for Jeep Wrangler 2007-2017 All Engine 3.21 Front Axle Ratio, Dana 30 only. Fit 3.21 Front Axle Ratio Dana 30 only, NOT fit 4.10 Axle Ratio Dana 44.