X0609 4 2026-08-21 0001411207 Allison Transmission Holdings Inc ALSN 0001543492 Graziosi David S. false C/O ALLISON TRANSMISSION HOLDINGS, INC. ONE ALLISON WAY INDIANAPOLIS IN 46222 true true false false Chair, President and CEO false Common Stock 2026-08-21 4 M false 26708 38.11 A 331551 D Common Stock 2026-08-21 4 S false 13100 132.4362 D 318451 D Common Stock 2026-08-21 4 S false 9050 133.2116 D 309401 D Common Stock 2026-08-21 4 S false 4558 134.0479 D 304843 D Employee Stock Option (right to buy) 38.11 2026-08-21 4 M false 26708 0 D 2032-02-24 Common Stock 26708 17593 D The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $132.000000 to $132.990000. The reporting person undertakes to provide Allison Transmission Holdings, Inc. ("ALSN") or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $133.000000 to $133.360000. The reporting person undertakes to provide ALSN or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The price reported is a weighted average price. The shares were sold in multiple transactions at per share prices ranging from $134.000000 to $134.120000. The reporting person undertakes to provide ALSN or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. This option vested in three equal annual installments beginning on February 24, 2023. /s/ Preston B. Ray, attorney-in-fact 2026-08-25