SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ONEX CORP (Last) (First) (Middle) 161 BAY STREET (Street) TORONTO A6 M5J 2S1 (City) (State) (Zip)	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)
	3. Date of Earliest Transaction (Month/Day/Year) 08/12/2013
	4. If Amendment, Date of 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

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)

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* ONEX CORP (Last) (First) (Middle) 161 BAY STREET (Street) TORONTO A6 M5J 2S1 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SCHWARTZ GERALD W (Last) (First) (Middle) C/O ONEX CORPORATION 161 BAY STREET (Street) TORONTO A6 M5J 2S1 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Onex American Holdings II LLC (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Onex American Holdings GP LLC (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Allison Executive Investco LLC (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Allison Executive Investco II LLC (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Onex American Holdings Subco LLC (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* OAH Wind LLC (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Onex Allison Holding Ltd S.A.R.L. (Last) (First) (Middle) 421 LEADER STREET (Street) MARION OH 43302 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

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 of OAH Wind LLC, which OAH Wind LLC and Allison Executive Investco II LLC own all of the equity 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 Partners GP Inc., Onex US Principals LP, Onex Partners II GP LP, Onex Allison Co-Invest LP, Onex Partners II LP, 1597257 Ontario Inc. and New PCo Investments Ltd. are filing a separate Form 4.

	ONEX CORPORATION, By: /s/ Andrea E. Daly, Authorized Person	08/14/2013
	/s/ Donald W. Lewtas, attorney-in-fact	08/14/2013
	ONEX AMERICAN HOLDINGS II LLC, By: /s/ Donald F. West, Authorized Person	08/14/2013
	ONEX AMERICAN HOLDINGS GP LLC, By: /s/ Donald F. West, Authorized Person	08/14/2013
	ALLISON EXECUTIVE INVESTCO LLC, By: /s/ Donald F. West, Authorized Person	08/14/2013
	ALLISON EXECUTIVE INVESTCO II LLC, By: /s/ Donald F. West, Authorized Person	08/14/2013
	ONEX AMERICAN HOLDINGS SUBCO LLC, By: /s/ Donald F. West, Authorized Person	08/14/2013
	OAH WIND LLC, By: /s/ Donald F. West, Authorized Person	08/14/2013
	ONEX ALLISON HOLDING LIMITED S.? R.L., By: /s/ Donald F. West, Authorized Person	08/14/2013
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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