EXHIBIT 5.1

                                 March 18, 2004

Tenneco Automotive Inc.
500 North Field Drive
Lake Forest, Illinois 60045

         Re: Registration Statement on Form S-8
             2,000,000 Shares of Common Stock
             --------------------------------
Ladies and Gentlemen:

        This opinion is furnished to you in connection with the Registration
Statement on Form S-8 under the Securities Act of 1933, as amended (the
"Registration Statement"), to be filed with the Securities and Exchange
Commission on March 18, 2004, relating to 2,000,000 shares (the "Shares") of
Common Stock, $0.01 par value (the "Common Stock"), of Tenneco Automotive Inc.
(the "Company") issuable pursuant to the Tenneco Automotive Inc. 2002 Long-Term
Incentive Plan (As Amended and Restated Effective March 11, 2003) (the "Plan").

        I have acted as General Counsel to the Company and am familiar with the
proceedings taken by the Company in connection with the authorization of the
Plan. In addition, in rendering the opinions expressed herein, I have examined
and relied upon such documents, corporate records, certificates of public
officials and certificates as to factual matters executed by officers of the
Company as I have deemed necessary or appropriate. I have assumed the
authenticity, accuracy and completeness of the originals of all documents,
records and certificates submitted to me as copies. I have also assumed the
legal capacity and genuineness of the signatures of persons signing all
documents in connection with which the opinions expressed herein are rendered.

        Based upon the foregoing, I am of the opinion that the Shares of Common
Stock are duly authorized for issuance and, when issued in accordance with the
provisions of the Plan, will be validly issued, fully paid and non-assessable
shares of Common Stock of the Company.

        I hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.

        I am admitted to practice law in the State of Illinois, and I express no
opinion as to matters under or involving any laws other than the laws of the
State of Illinois, the federal laws of the United States of America and the
General Corporation Law of the State of Delaware.

                                    Very truly yours,



                                     /s/ Timothy R. Donovan
                                    --------------------------------------------

                                    Timothy R. Donovan
                                    Executive Vice President, General Counsel
                                    and Managing Director - International
                                    Tenneco Automotive Inc.