Exhibit 99

Joint Filer Information

Date of Event Requiring Statement:	March 20, 2012
Issuer Name and Ticker or Trading Symbol:	Allison Transmission Holdings, Inc. [ALSN]
Designated Filer:	Onex Corporation
Other Joint Filers:	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 Onex Allison Holding Limited S.á.R.L. Onex US Principals LP Onex Partners GP Inc. Onex Partners II GP LP Onex Allison Co-Invest LP Onex Partners II LP 1597257 Ontario Inc. Onex Advisor III LLC Onex Advisor Subco LLC
Addresses:	The address of each of the reporting persons is c/o Onex Corporation, 161 Bay Street, Toronto, ON M5J 2S1.

Signatures:

Dated: March 22, 2012

ONEX CORPORATION
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
GERALD W. SCHWARTZ
By:	/s/ Gerald W. Schwartz
Name:	Gerald W. Schwartz
ONEX AMERICAN HOLDINGS II LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX AMERICAN HOLDINGS GP LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ALLISON EXECUTIVE INVESTCO LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ALLISON EXECUTIVE INVESTCO II LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX AMERICAN HOLDINGS SUBCO LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
OAH WIND LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX ALLISON HOLDING LIMITED S.Á.R.L.
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX US PRINCIPALS LP
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX PARTNERS GP INC.
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX PARTNERS II GP LP
By Onex Partners GP Inc., General Partner
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX ALLISON CO-INVEST LP
By Onex Partners II GP LP, General Partner
By Onex Partners Manager LP, its Agent
By Onex Partners Manager GP ULC, its General Partner
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX PARTNERS II LP
By Onex Partners II GP LP, General Partner
By Onex Partners Manager LP, its Agent
By Onex Partners Manager GP ULC, its General Partner
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
1597257 ONTARIO INC.
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX ADVISOR III LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person
ONEX ADVISOR SUBCO LLC
By:	/s/ Andrea E. Daly
Name:	Andrea E. Daly
Title:	Authorized Person