SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

Allison Transmission Holdings, Inc.

(Name of Issuer)

Common stock, par value $0.01

(Title of Class of Securities)

01973R101

(CUSIP Number)

June 9, 2014

(Date of Event Which Requires Filing of this Statement)

Check the following box to designate the rule pursuant to which the Schedule is filed:

¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Not Applicable

As of June 9, 2014:

David E. Shaw does not own any shares directly. By virtue of David E. Shaw’s position as President and sole shareholder of D. E. Shaw & Co., Inc., which is the general partner of D. E. Shaw & Co., L.P., which in turn is the manager and investment adviser of D. E. Shaw Valence Portfolios, L.L.C., the investment adviser of D. E. Shaw Oculus Portfolios, L.L.C., and the managing member of (i) D. E. Shaw Investment Management, L.L.C., (ii) D. E. Shaw Heliant Adviser, L.L.C., which in turn is the investment adviser of D. E. Shaw Kalon Portfolios, L.L.C., and (iii) D. E. Shaw Adviser, L.L.C., which in turn is the investment adviser of D. E. Shaw Asymptote Portfolios, L.L.C., and by virtue of David E. Shaw’s position as President and sole shareholder of D. E. Shaw & Co. II, Inc., which is the managing member of D. E. Shaw & Co., L.L.C., which in turn is the manager of D. E. Shaw Oculus Portfolios, L.L.C. and the managing member of (i) D. E. Shaw Heliant Manager, L.L.C., which in turn is the manager of D. E. Shaw Kalon Portfolios, L.L.C., and (ii) D. E. Shaw Manager, L.L.C., which in turn is the manager of D. E. Shaw Asymptote Portfolios, L.L.C., David E. Shaw may be deemed to have the shared power to vote or direct the vote of 8,813,581 shares, and the shared power to dispose or direct the disposition of 8,900,781 shares, the 8,900,781 shares as described above constituting 5.0% of the outstanding shares and, therefore, David E. Shaw may be deemed to be the beneficial owner of such shares. David E. Shaw disclaims beneficial ownership of such 8,900,781 shares.

Not Applicable

Not Applicable

Not Applicable

Not Applicable

Not Applicable

By signing below, each of D. E. Shaw & Co., L.P. and David E. Shaw certify that, to the best of such reporting person’s knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having such purposes or effect.

SIGNATURE

After reasonable inquiry and to the best of their knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct. A Power of Attorney, dated June 22, 2012, granted by David E. Shaw in favor of Nathan Thomas, is attached hereto.

Dated: June 19, 2014

Exhibit 1

POWER OF ATTORNEY

FOR CERTAIN REGULATORY FILINGS

INCLUDING CERTAIN FILINGS

UNDER THE SECURITIES EXCHANGE ACT OF 1934

AND THE INVESTMENT ADVISERS ACT OF 1940

I, David E. Shaw, hereby make, constitute, and appoint each of:

Anne Dinning,

Julius Gaudio,

John Liftin,

Louis Salkind,

Maximilian Stone,

Nathan Thomas, and

Eric Wepsic,

acting individually, as my agent and attorney-in-fact, with full power of substitution, for the purpose of, from time to time, (i) executing in my name and/or my capacity as President of D. E. Shaw & Co., Inc. (acting for itself or as the general partner of D. E. Shaw & Co., L.P. and general partner, managing member, or manager of other entities, any of which in turn may be acting for itself or other entities) all documents, certificates, instruments, statements, other filings, and amendments to the foregoing (collectively, “documents”) determined by such person to be necessary or appropriate to comply with any registration or regulatory disclosure requirements and/or ownership or control-person reporting requirements imposed by any United States or non-United States governmental or regulatory authority, including without limitation Form ADV, Forms 3, 4, 5, and 13F, and Schedules 13D and 13G required to be filed with the United States Securities and Exchange Commission, and (ii) delivering, furnishing, or filing any such documents to or with the appropriate governmental or regulatory authority. Any such determination shall be conclusively evidenced by such person’s execution, delivery, furnishing, and/or filing of the applicable document.

This power of attorney shall be valid from the date hereof and replaces the power granted on December 15, 2011, which is hereby cancelled.

IN WITNESS HEREOF, I have executed this instrument as of the date set forth below.

Date: June 22, 2012

Exhibit 2

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, each of the undersigned Reporting Persons hereby agrees to the joint filing, along with all other such Reporting Persons, on behalf of each of them of a statement on Schedule 13G (including amendments thereto) with respect to the Common stock, par value $0.01, of Allison Transmission Holdings, Inc., and that this Agreement be included as an Exhibit to such joint filing. This Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument.

IN WITNESS WHEREOF, each of the undersigned hereby executes this Agreement as of this 19^th day of June, 2014.