Accuride Corp (ACW): Coliseum Capital Slightly Ups Its Stake

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No.     )*

ACCURIDE
CORPORATION

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)

00439T206

(CUSIP Number)

Christopher Shackelton/Adam Gray

Metro Center

1 Station
Place, 7th Floor South

Stamford, CT 06902

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

May 24, 2016

(Date of Event Which Requires Filing of This Statement)

If the filing person has
previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box.  x

The information required on 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, as amended, (the Exchange Act) or otherwise subject to the liabilities of that section of the Exchange Act but shall be
subject to all other provisions of the Exchange Act (however, see the Notes).

This Schedule 13D (this Schedule 13D) supersedes the Schedule 13G as last amended by
Amendment No. 6 filed on February 16, 2016 with the Securities and Exchange Commission (the SEC) by Coliseum Capital Management, LLC (CCM), Coliseum Capital, LLC (CC), Coliseum
Capital Partners, L.P. (CCP), Coliseum Capital Partners II, L.P. (CCP2), Adam Gray (Gray) and Christopher Shackelton (Shackelton), relating to shares of common stock, $0.01
par value per share (the Common Stock), of Accuride Corporation (the Issuer), a corporation organized under the laws of Delaware. This Schedule 13D is being filed because the Reporting Persons may no longer
qualify to file on Schedule 13G. See Item 4 below.

Item 1. Security and Issuer.

This Schedule 13D relates to shares of the common stock, $0.01 par value per share, of Accuride Corporation, a corporation organized under the laws of
Delaware. The principal executive offices of the Issuer are located at 7140 Office Circle, Evansville, IN 47715.

Item 2. Identity and Background.

The persons filing this statement and the persons enumerated in Instruction C of Schedule 13D and, where applicable, their respective places of
organization, general partners, directors, executive officers and controlling persons and the information regarding them, are as follows:

The foregoing persons are hereinafter sometimes collectively referred to as the
Reporting Persons.

CCM is the investment adviser to CCP and CCP2, which are investment limited partnerships. CC is the General Partner of CCP
and CCP2. Gray and Shackelton are the managers of CC and CCM.

Item 3. Source and Amount of Funds or Other Consideration.

The source and amount of funds used in purchasing the Common Stock by the Reporting Persons and a separate account investment advisory client of CCM (the
Separate Account) were as follows:

Item 4. Purpose of Transaction.

The Reporting Persons acquired the Common Stock for investment purposes in the Reporting Persons ordinary course of business. In addition, the Reporting
Persons collectively beneficially own $52,508,000 in principal amount of the Issuers 9.5% first lien bonds (the Bonds and, together with the Common Stock, the Securities) for investment purposes in the ordinary course
of the Reporting Persons business. In pursuing such investment purposes, the Reporting Persons may further purchase, hold, vote, trade, dispose or otherwise deal in the Securities at times, and in such manner (including pursuant to hedging
transactions), as they deem advisable to benefit from changes in market prices of the Securities, changes in the Issuers operations, business strategy or prospects, or from a sale or merger of the Issuer. To evaluate such alternatives, the
Reporting Persons routinely will monitor the Issuers operations, prospects, business development, management, competitive and strategic matters, capital structure, and prevailing market conditions, as well as alternative investment
opportunities, liquidity requirements of the Reporting Persons and other investment considerations. Consistent with their investment research methods and evaluation criteria, the Reporting Persons may discuss such matters with management or
directors of the Issuer, other shareholders, industry analysts, existing or potential strategic partners or competitors, investment and financing professionals, sources of credit and other investors. Such factors and discussions may materially
affect, and result in, the Reporting Persons modifying their ownership of the Securities, exchanging information with the Issuer pursuant to appropriate confidentiality or similar agreements, proposing changes in the Issuers operations,
governance or capitalization, or in proposing one or more of the other actions described in paragraphs (a) through (j) of Item 4 of Schedule 13D. The Reporting Persons reserve the right to formulate other plans and/or make other
proposals and take such actions with respect to their investment in the Issuer, including any or all of the actions set forth in paragraphs (a) through (j) of Item 4 of Schedule 13D, or acquire additional Securities or dispose of all
Securities beneficially owned by them, in public market or privately negotiated transactions. The Reporting Persons may at any time reconsider and change their plans or proposals relating to the foregoing.

Item 5. Interest in Securities of the Issuer.

The information required by Items 5(a) (b) is set forth in rows 7 13 of
the cover page for each of the Reporting Persons and is incorporated herein by reference.

The information in Items 4 and 6 hereof is incorporated herein by reference.

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

CCM is an investment adviser whose clients, including CCP, CCP2 and the Separate Account, have the right to receive or the power to direct the receipt of
dividends from, or the proceeds from the sale of, the Common Stock. CC is the general partner of CCP and CCP2. Gray and Shackelton are the managers of CC and CCM.

The Reporting Persons are parties to an agreement with respect to the joint filing of this Schedule 13D and
any amendments thereto. A copy of such agreement is filed as Exhibit 1 to this Schedule 13D and is incorporated by reference herein.

The information in
Item 4 hereof is incorporated herein by reference.

Item 7. Material to Be Filed as Exhibits.

SIGNATURES

After reasonable inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in this
statement is true, complete and correct

DATED: May 24, 2016