2012 Allison 2500PTS, School Bus, Transmission Assys, Fits to: Thomas Built Saf-T-Liner HDX, (Used) 2011 Allison (AT), TRANSMISSION ASSEMBLY- Model: 2500PTS, Serial Number: 6311044821, Engine: Cummins ISL, For more information about this item, give us a call. We ship worldwide! (CRG HAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921, Serial# 6311044821, Truck Year 2012, VIN 1T7YN4E24C1146909 1T7YN4E24C1146909