Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Onex Partners GP Inc.
  2. Issuer Name and Ticker or Trading Symbol
Allison Transmission Holdings Inc [ALSN]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
712 FIFTH AVENUE, 40TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
08/12/2013
(Street)

NEW YORK, NY 10019
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 08/12/2013   S   11,902,500 D $ 21.175 63,446,249 I See Footnotes (1) (2) (3) (4) (5)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Onex Partners GP Inc.
712 FIFTH AVENUE
40TH FLOOR
NEW YORK, NY 10019
    X    
Onex US Principals LP
421 LEADER STREET
MARION, OH 43302
    X    
Onex Partners II GP LP
712 FIFTH AVENUE
40TH FLOOR
NEW YORK, NY 10019
    X    
Onex Allison Co-Invest LP
712 FIFTH AVENUE
40TH FLOOR
NEW YORK, NY 10019
    X    
ONEX PARTNERS II L P
712 FIFTH AVENUE
40TH FLOOR
NEW YORK, NY 10019
    X    
1597257 Ontario Inc.
C/O ONEX CORPORATION
161 BAY STREET
TORONTO, A6 M5J 2S1
    X    
New PCo Investments Ltd.
C/O ONEX CORPORATION
161 BAY STREET
TORONTO, A6 M5J 2S1
    X    

Signatures

 ONEX PARTNERS GP INC., By: /s/ Andrea E. Daly, Authorized Person   08/14/2013
**Signature of Reporting Person Date

 ONEX US PRINCIPALS LP, By: /s/ Donald F. West, Authorized Person   08/14/2013
**Signature of Reporting Person Date

 ONEX PARTNERS II GP LP, By: Onex Partners GP Inc., its general partner, By: /s/ Andrea E. Daly, Authorized Person   08/14/2013
**Signature of Reporting Person Date

 ONEX ALLISON CO-INVEST LP, By: Onex Partners II GP LP, its general partner, By: Onex Partners Manager LP, its Agent, By: Onex Partners Manager GP ULC, its general partner, By: /s/ Andrea E. Daly, Authorized Person   08/14/2013
**Signature of Reporting Person Date

 ONEX PARTNERS II LP, By Onex Partners II GP LP, its general partner, By Onex Partners Manager LP, its Agent, By Onex Partners Manager GP ULC, its general partner, By: /s/ Andrea E. Daly, Authorized Person   08/14/2013
**Signature of Reporting Person Date

 1597257 ONTARIO INC., By: /s/ Andrea E. Daly, Authorized Person   08/14/2013
**Signature of Reporting Person Date

 NEW PCO INVESTMENTS LTD., By: /s/ Andrea E. Daly, Authorized Person   08/14/2013
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Includes: (i) 28,683,478 shares of common stock held by Onex Partners II LP; (ii) 19,283,704 shares of common stock held by Onex Allison Holding Limited S.a R.L.; (iii) 13,521,331 shares of common stock held by Onex Allison Co-Invest LP; (iv) 540,367 shares of common stock held by Onex US Principals LP; and (v) 269,594 shares of common stock held by Onex Partners II GP LP.
(2) Onex Corporation may be deemed to beneficially own the common stock held by (a) Onex Partners II LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP, the general partner of Onex Partners II LP; (b) Onex Allison Holding Limited S.a R.L., through Onex Corporation's ownership of all of the equity of Onex American Holdings II LLC, which owns all of the equity of each of Allison Executive Investco LLC, which owns all of the equity of Allison Executive Investco II LLC, and Onex American Holdings Subco LLC, which owns all of the equity interests of OAH Wind LLC, which OAH Wind LLC and Allison Executive Investco II LLC own all of the equity interests of Onex Allison Holding Limited S.a R.L.; (continued)
(3) (c) Onex Allison Co-Invest LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP, the general partner of Onex Allison Co-Invest LP; (d) Onex US Principals LP, through Onex Corporation's ownership of all of the equity of Onex American Holdings II LLC, which owns all of the equity of Onex American Holdings GP LLC, the general partner of Onex US Principals LP; and (e) Onex Partners II GP LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP.
(4) New PCo Investments Ltd. is the record holder of 1,361,911 shares of common stock and 1,185 shares of non-voting common stock. 1597257 Ontario Inc., the sole shareholder of New PCo Investments Ltd., is an independent entity that is controlled by Mr. Gerald W. Schwartz. Mr. Schwartz, the Chairman, President and Chief Executive Officer of Onex Corporation, owns shares representing a majority of the voting rights of the shares of Onex Corporation and as such may be deemed to beneficially own all of the common stock owned beneficially by Onex Corporation. Mr. Schwartz disclaims any such beneficial ownership. Mr. Schwartz has indirect voting and investment control of Onex Corporation.
(5) Due to the limitations of the electronic filing system, Onex Corporation, Gerald W. Schwartz, Onex American Holdings II LLC, Onex American Holdings GP LLC, Allison Executive Investco LLC, Allison Executive Investco II LLC, Onex American Holdings Subco LLC, OAH Wind LLC and Onex Allison Holding Limited S.a R.L. are filing a separate Form 4.

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