Quick view AEV ProCal Module - Jeep JK $170.00 Important Notes: Sold individually WILL enable axle gear ratio changes to be made to JK models equipped with A580 automatic transmission (2011+ 2.8L, 2012+ 3.6L). CANNOT change axle gear ratios for 2011+ JK models with a 2.8L CRD diesel and a manual... Compare Add to Cart