<PAGE>


                                                                  EXHIBIT 4.5(c)


                     FIRST AMENDMENT TO THE CREDIT AGREEMENT


                  FIRST AMENDMENT, dated as of April 30, 2004 (this "First
Amendment"), to the Amended and Restated Credit Agreement, dated as of December
12, 2003 (amending and restating the Credit Agreement dated as of September 30,
1999) (as amended, supplemented, or otherwise modified from time to time, the
"Credit Agreement"), among TENNECO AUTOMOTIVE INC., a Delaware corporation (the
"Borrower"), the several lenders from time to time parties thereto (the
"Lenders"), JPMORGAN CHASE BANK, a New York banking corporation, as
administrative agent for the Lenders (in such capacity, the "Administrative
Agent"), and the other financial institutions named therein as agents for the
Lenders (in such capacity, collectively, the "Other Agents").

                                   WITNESSETH:

                  WHEREAS, the Borrower, the Lenders and the Administrative
Agent and the Other Agents are parties to the Credit Agreement;

                  WHEREAS, the Borrower has notified the Lenders of its
intention to refinance its existing senior subordinated notes from time to time
(as hereinafter further defined, the "Senior Subordinated Notes");

                  WHEREAS, the Borrower has requested that the Lenders amend the
Credit Agreement as set forth herein;

                  WHEREAS, the Lenders, the Administrative Agent and the Other
Agents are willing to agree to such amendment to the Credit Agreement, subject
to the terms and conditions set forth herein;

                  NOW, THEREFORE, in consideration of the premises and mutual
covenants contained herein, the Borrower, the Lenders, the Administrative Agent
and the Other Agents hereby agree as follows:

                  1. Defined Terms. Unless otherwise defined herein, capitalized
terms which are defined in the Credit Agreement are used herein as therein
defined.

                  2. Amendments to Credit Agreement. (a) Section 1.1 of the
Credit Agreement is amended as follows:

                  (i) by adding the following sentence at the end of the
                  definition of "Second Lien Notes":

                  Upon the issuance of any Permitted Refinancing Indebtedness in
                  respect of any Notes, such Permitted Refinancing Indebtedness
                  shall be deemed to be Second Lien Notes (in addition to any
                  other Second Lien Notes that are then outstanding).

                  and (ii) by adding the following sentence at the end of the
                  definition of "Second Lien Note Indenture":



<PAGE>


                                                                               2


                  Upon the issuance of any Permitted Refinancing Indebtedness in
                  respect of any Second Lien Notes, the indenture or similar
                  agreement pursuant to which such Permitted Refinancing
                  Indebtedness is issued shall be deemed to be a Second Lien
                  Note Indenture (in addition to any other indenture or similar
                  agreement for Second Lien Notes then outstanding); provided,
                  however, that (1) the provisions of Section 4.22 shall apply
                  to such indenture or similar agreement pursuant to which such
                  Permitted Refinancing Indebtedness is issued only if such
                  indenture or agreement (or any agreement ancillary thereto) is
                  secured by any assets of the Borrower or its Subsidiaries, and
                  (2) the provisions of Section 7.9(c) shall not apply to such
                  indenture or similar agreement pursuant to which such
                  Permitted Refinancing Indebtedness is issued.;

                  (iii) by adding the following sentence at the end of the
                  definition of "Senior Subordinated Notes":

                  Upon the issuance of any Permitted Refinancing Indebtedness in
                  respect of any Senior Subordinated Notes, such Permitted
                  Refinancing Indebtedness shall be deemed to be Senior
                  Subordinated Notes (in addition to any other Senior
                  Subordinated Notes that are then outstanding).

                  and (iv) by adding the following sentence at the end of the
                  definition of "Senior Subordinated Note Indenture":

                  Upon the issuance of any Permitted Refinancing Indebtedness in
                  respect of any Senior Subordinated Notes, the indenture or
                  similar agreement pursuant to which such Permitted Refinancing
                  Indebtedness is issued shall be deemed to be a Senior
                  Subordinated Note Indenture (in addition to any other
                  indenture or similar agreement for Senior Subordinated Notes
                  then outstanding); provided, however (1) the provisions of
                  Section 7.9(c) shall apply to such indenture or similar
                  agreement pursuant to which such Permitted Refinancing
                  Indebtedness is issued only if such indenture or agreement
                  includes a provision regarding "Designated Senior Debt"
                  similar to that included in the Indenture, dated as of October
                  14, 1999 between the Borrower and The Bank of New York, as
                  trustee (the "1999 Indenture"), and (2) the provisions of
                  Section 4.21 shall apply to such indenture or similar
                  agreement pursuant to which such Permitted Refinancing
                  Indebtedness is issued only if such indenture or agreement
                  includes a provision regarding the designation of "Senior
                  Debt" of the Borrower or "Guarantor Senior Debt" of any
                  Subsidiary Guarantor, as applicable, similar to those included
                  in the 1999 Indenture.

(b) Section 7.9 of the Credit Agreement is amended by deleting the parenthetical
immediately after the words "Senior Subordinated Indenture" and adding the
following parenthetical:

         (other than any such amendment, modification, waiver or other change
         that (x) (i) would extend the maturity or reduce the amount of any
         payment of principal thereof or reduce the rate or extend any date for
         payment of interest thereon and (ii) does not involve the payment of a
         consent fee or (y) is not adverse to the Lenders)



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                                                                               3


(c) Section 6.9(f) of the Credit Agreement is amended by inserting the words
"Second Lien Note" immediately before the word "Indenture" therein;

(d) Section 8.1(m) of the Credit agreement is amended by deleting the phrase
"pursuant to a Permitted Second Lien Notes Refinancing" immediately after the
word "interest" and adding "or as permitted by the last section of Section
7.15."

                  3. Refinancing of Senior Subordinated Notes. The Lenders (a)
consent to the amendments to the existing Senior Subordinated Note Indenture on
the terms set forth in the Offer to Purchase and Consent Solicitation Statement
dated April 30, 2004 ("Offer to Purchase") and (b) consent to the purchase,
payment, prepayment, defeasance, retirement or other acquisition by the Borrower
of the existing Senior Subordinated Notes remaining outstanding after completion
of the Offer to Purchase as long as (1) no Default or Event of Default has
occurred and is continuing and (2) the transaction takes place on or prior to
December 31, 2004. The Lenders further agree that the provisions of Section 2.13
of the Credit Agreement shall not apply to the Net Cash Proceeds of any issuance
or incurrence by the Borrower or any of its Subsidiaries of any Capital Stock or
Indebtedness to the extent, but only to the extent, such Net Cash Proceeds are
used to effect one or more transactions in accordance with the foregoing clause
(b).

                  4. Representations and Warranties. The Borrower hereby
confirms that the representations and warranties set forth in Section 4 of the
Credit Agreement, as amended by this First Amendment, are true and correct in
all material respects as if made as of the Effective Date (except such
representations and warranties as are made as of a particular date, which such
representations and warranties shall be true and correct in all material
respects as if made as of such date). The Borrower represents and warrants that,
after giving effect to this First Amendment, no Default or Event of Default has
occurred and is continuing.

                  5. Effectiveness. This First Amendment shall become effective
as of the date of receipt by the Administrative Agent of counterparts of this
First Amendment executed by the Borrower and the Required Lenders (the
"Effective Date").

                  6. Continuing Effect of the Credit Agreement. This First
Amendment shall not constitute an amendment of any provision of the Credit
Agreement not expressly referred to herein and shall not be construed as a
waiver or consent to any further or future action on the part of the Borrower
that would require a waiver or consent of the Lenders, the Administrative Agent
or the Other Agents. Except as expressly amended hereby, the provisions of the
Credit Agreement are and shall remain in full force and effect.

                  7. Counterparts. This First Amendment may be executed by the
parties hereto in any number of separate counterparts (including telecopied
counterparts), each of which shall be deemed to be an original, and all of which
taken together shall be deemed to constitute one and the same instrument.



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                                                                               4


                  8. GOVERNING LAW. THIS FIRST AMENDMENT SHALL BE GOVERNED BY,
AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW
YORK.



<PAGE>


                  IN WITNESS WHEREOF, the parties hereto have caused this First
Amendment to be duly executed and delivered by their respective proper and duly
authorized officers as of the day and year first above written.

                                       TENNECO AUTOMOTIVE INC.



                                       By:
                                           -------------------------------------
                                           Name:
                                           Title:



                                       JPMORGAN CHASE BANK, as Administrative
                                       Agent and as a Lender

                                       By:
                                           -------------------------------------
                                           Name:
                                           Title:



                                       DEUTSCHE BANK SECURITIES INC., as
                                       Syndication Agent and as a Lender



                                       By:
                                           -------------------------------------
                                           Name:
                                           Title:



<PAGE>


                                       FIRST AMENDMENT dated as of April 30,
                                       2004 to the Tenneco Automotive Inc.
                                       Amended and Restated Credit Agreement,
                                       dated as of December 12, 2003 (amending
                                       and restating the Credit Agreement dated
                                       as of September 30, 1999)



                                       -----------------------------------------
                                                       [LENDER]



                                       By:
                                           -------------------------------------
                                           Name:
                                           Title:



<PAGE>


Each of the undersigned agrees to the foregoing
First Amendment and confirms that its
obligations under the Loan Documents to
which it is a party remain in full force and
effect after giving effect to such Fourth
Amendment:


TENNECO AUTOMOTIVE OPERATING COMPANY INC.
TENNECO INTERNATIONAL HOLDING CORP.
TENNECO GLOBAL HOLDINGS INC.
THE PULLMAN COMPANY
TMC TEXAS INC.
CLEVITE INDUSTRIES INC.



By:
   -----------------------------------
   Name:
   Title: