Product Update: 11.5" and 11.8" Gear Sets and Differential Cases
Posted: May 20, 2019
The 40099548 is a 3 pinion helical gear design limited slip differential case and is used with the 11.5" GM and RAM gear sets from 2001-2018. The same differential case is used for the 11.8" gear sets used in the 2014-2015 RAM rear axle. All of these 11.5" and 11.8" gear sets have a 12 bolt ring gear mounting pattern.
The 40149229 is a 4 pinion helical gear design limited slip differential case and is used with 11.8" gear sets in the 2016-2018 RAM truck rear axle. This differential case and the corresponding gear sets have a 16 ring gear bolt pattern.
Please make a note of these differences for your information. If you have any questions regarding this information, please call AAM Driveline Aftermarket customer service or your AAM sales representative.