Allison Transmission Holdings Inc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the Securities

Exchange Act of 1934 (Amendment No. )

Filed by the Registrant ☑

Filed by a Party other than the Registrant ☐

Check the appropriate box:

ALLISON TRANSMISSION HOLDINGS, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

Dear Fellow Stockholder:

I am pleased to present the 2024 Allison Transmission Holdings, Inc., or Allison, proxy statement, which contains information about Allison’s strategic direction, corporate responsibility and sustainability efforts, executive compensation, governance and Board of Directors’ composition. It is my pleasure, along with our Board of Directors, or Board, to invite you to the 2024 annual meeting of stockholders, or the Annual Meeting, of Allison. This year’s Annual Meeting will be held on Wednesday, May 8, 2024 at 10:00 a.m. Eastern Time in a virtual format only, via live webcast at www.virtualshareholdermeeting.com/ALSN2024. There will not be a physical location for our Annual Meeting, and you will not be able to attend the meeting in person.

You will find information regarding the business to be conducted at the Annual Meeting in the attached Notice of 2024 Annual Meeting of Stockholders and Proxy Statement, including information you should consider when you vote your shares. We are sending substantially all of our stockholders a Notice of Internet Availability of Proxy Materials, our 2023 Annual Report to Stockholders and other proxy materials via the Internet. This electronic process gives you fast, convenient access to the materials, diminishes our impact on the environment and reduces our printing and mailing costs. A paper copy of these materials can be requested using one of the methods described in the materials.

Whether or not you plan to attend the Annual Meeting, your vote is important, and we encourage you to vote promptly. You may vote your shares by telephone, via the Internet or, if you received a paper copy of the proxy materials, by signing, dating and returning your proxy card or voting instruction form.

Our Board unanimously recommends that you vote:

Allison achieved record revenues of $3 billion in 2023 led by robust demand in our North America On-Highway end market, which was up 13 percent year-over-year, driven by strength in demand for Class 8 vocational and medium-duty trucks and record revenues in our Service Parts, Support Equipment and Other end market, which was up 18 percent year-over-year, driven by aging fleets and increased demand for Allison genuine service parts. We also continued to invest in product development and innovations across our product portfolio to advance the next generation of commercial duty vehicle propulsion technologies that will improve fuel efficiency and facilitate the transition to zero emissions. Finally, we returned capital to our stockholders in 2023 by increasing our quarterly dividend for the fourth consecutive year and repurchasing $263 million of our shares of common stock, representing nearly 6 percent of our shares of common stock outstanding as of December 31, 2022.

I appreciate your continued interest in and support of our Company and look forward to speaking to you at the Annual Meeting.

Sincerely,

David S. Graziosi

Chair, President and Chief Executive Officer

Wednesday, May 8, 2024

10:00 a.m. Eastern Time

To be held virtually at www.virtualshareholdermeeting.com/ALSN2024

Record Date

March 11, 2024

Items of Business

Our Board unanimously recommends that you vote:

Admission

In order to attend the Annual Meeting, please visit www.virtualshareholdermeeting.com/ALSN2024 and enter the 16-digit control number included in your Notice of Internet Availability of Proxy Materials or on your proxy card or voting instruction form. Online access to the Annual Meeting will begin at 9:45 a.m. Eastern Time on May 8, 2024 to allow time to log-in and test your device’s audio system. We encourage you to access the Annual Meeting in advance of the designated start time.

Voting

Your Vote is Important. Please vote your shares at your earliest convenience. This will ensure the presence of a quorum at the Annual Meeting. Promptly voting your shares via the Internet, by telephone, or, if you received a paper copy of the proxy materials, by signing, dating and returning the accompanying proxy card or voting instruction form, will save the expense and extra work of additional solicitation. Submitting your proxy now will not prevent you from voting your shares online during the live webcast of the Annual Meeting, as your proxy is revocable at your option.

On or about Friday, March 29, 2024, we will mail to our stockholders either (1) a copy of this proxy statement, a proxy card and our 2023 Annual Report to Stockholders, or (2) a Notice of Internet Availability of Proxy Materials, which will indicate how to access our proxy materials and vote via the Internet.

The Notice of Internet Availability of Proxy Materials, proxy statement, form of proxy card and our 2023 Annual Report to Stockholders are available at www.proxyvote.com.

The accompanying proxy statement provides a detailed description of the business to be conducted at the Annual Meeting. We urge you to read the accompanying proxy statement carefully and in its entirety.

By order of the Board of Directors

Eric C. Scroggins

Vice President, General Counsel & Secretary