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                                                                     EXHIBIT 4.3

                  SECOND SUPPLEMENTAL INDENTURE, dated as of May 30, 2002 (this
"Second Supplemental Indenture"), by and between Quality Distribution, Inc., a
Florida corporation (the "Company"), the subsidiaries of the Company listed on
the signature pages hereto (the "Guarantors"), and The Bank of New York, as
trustee (the "Trustee").

                              W I T N E S S E T H:

                  WHEREAS, the Company, the Guarantors and the Trustee have
entered into that certain Indenture, dated as of June 9, 1998, as supplemented
by the First Supplemental Indenture, dated as of August 28, 1998 (as so
supplemented, the "Indenture"), providing for the issuance and delivery by the
Company of its 10% Series B Senior Subordinated Notes due 2006 and Series B
Floating Interest Rate Subordinated Term Securities (FIRSTS(SM)) due 2006
(collectively, the "Securities"); and

                  WHEREAS, there is currently outstanding under the Indenture an
aggregate principal amount of $140,000,000 of the Securities; and

                  WHEREAS, Section 9.02 of the Indenture provides that the
Company, the Guarantors and the Trustee may (subject to certain exceptions),
with the written consent of the holders (other than Affiliates (as defined in
the Indenture) of the Company) of at least a majority in aggregate principal
amount of the outstanding Securities, amend or supplement the Indenture for the
purpose of making certain modifications, waivers and amendments of the
provisions of the Securities or the Indenture; and

                  WHEREAS, the Company has offered to exchange (the "Exchange
Offer") all of the outstanding Securities upon the terms and subject to the
conditions set forth, as applicable, in (a) the Offering Memorandum and Consent
Solicitation Statement, dated April 10, 2002, as amended by Supplement No. 1
thereto, dated May 10, 2002, the related Consent and Letter of Transmittal,
dated April 10, 2002, and the related Institutional Accredited Investor Letter,
dated April 10, 2002 (collectively, as each such document may be amended,
supplemented or modified from time to time, the "Offering Memorandum"), (b) the
Lock-Up and Purchase Agreement, dated as of April 10, 2002, as amended by the
Waiver thereto dated May 10, 2002 (the "Apollo Lock-Up Agreement") among the
Company, Apollo Investment Fund III, L.P., Apollo Overseas Partners III, L.P.
and Apollo (U.K.) Partners III, L.P. (collectively, the "Apollo Entities"), (c)
the Lock-Up Agreement, dated as of April 10, 2002, as amended by Amendment No. 1
thereto dated May 24, 2002 (the "Ares Lock-Up Agreement"), among the Company,
ARES Leveraged Investment Fund, L.P. and ARES Leveraged Investment Fund II, L.P.
(collectively, the "Ares Entities") and (d) the Lock-Up Agreement, dated as of
April 10, 2002 (the "Management Group Lock-Up Agreement" and, together with the
Apollo Lock-Up Agreement and the Ares Lock-Up Agreement, collectively, the
"Lock-Up Agreements"), among the Company and certain members of management of
the Company (the "Management Group"); and

                  WHEREAS, in connection with the Exchange Offer, the Company is
soliciting consents (the "Consent Solicitation") from the holders (other than
Affiliates (as defined in the Indenture) of the Company) of at least a majority
in aggregate principal amount of the outstanding Securities (the "Requisite
Consents") to the proposed amendments (the "Proposed
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Amendments") to the Indenture, with the effectiveness of such Proposed
Amendments being conditioned only upon the receipt by the Company of the
Requisite Consents and the execution of this Second Supplemental Indenture; and

                  WHEREAS, the Company has received and delivered to the Trustee
the Requisite Consents to effect the Proposed Amendments under the Indenture and
has delivered an officers' certificate to the Trustee so certifying; and

                  WHEREAS, the Company has been authorized by a resolution of
its Board of Directors to enter into this Second Supplemental Indenture.

                  NOW, THEREFORE, in consideration of the premises and the
mutual agreements contained herein and for other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged, the
parties hereto agree as follows for the benefit of each other party and for the
equal and ratable benefit of the holders of the Securities:

                                    ARTICLE I

                                    AMENDMENT

1.1      AMENDMENT OF SECTION 1.01.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 1.01 of the Indenture are amended by deleting, in their entirety, those
terms, and the respective meanings assigned thereto, that are referred to solely
in the provisions of those Sections and subsections of the Indenture (other than
Section 1.01) that will be amended by deleting the text of such Section or
subsection, as the case may be, in its entirety (and inserting in lieu thereof
the phrase "[intentionally omitted]"), as a result of the execution of this
Second Supplemental Indenture.

1.2      AMENDMENT OF SECTION 4.03.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.03 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.3      AMENDMENT OF SECTION 4.04.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.04 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.4      AMENDMENT OF SECTION 4.05.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.05 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."
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1.5      AMENDMENT OF SECTION 4.06.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.06 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.6      AMENDMENT OF SECTION 4.07.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.07 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.7      AMENDMENT OF SECTION 4.09.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.09 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.8      AMENDMENT OF SECTION 4.10.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.10 are amended by deleting the text of such Section in its entirety
and inserting in lieu thereof the following: "The Company will deliver to the
Trustee, the Commission or the Holders of the Securities, as applicable, all
information, documents and other reports required to be delivered by the
provisions of Section 314(a) of the Trust Indenture Act of 1939, as amended."

1.9      AMENDMENT OF SECTION 4.12.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.12 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.10     AMENDMENT OF SECTION 4.13.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.13 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.11     AMENDMENT OF SECTION 4.14.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.14 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."
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1.12     AMENDMENT OF SECTION 4.17.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.17 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.13     AMENDMENT OF SECTION 4.18.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 4.18 of the Indenture are amended by deleting the text of such Section
in its entirety and inserting in lieu thereof the phrase "[intentionally
omitted]."

1.14     AMENDMENT OF SECTION 5.01.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 5.01 of the Indenture are amended as follows:

                  (a) subsection (a)(ii) thereof is deleted in its entirety;

                  (b) subsection (a)(iii) thereof is redesignated as subsection
(a)(ii);

                  (c) subsection (a)(iv) thereof is redesignated as subsection
(a)(iii);

                  (d) the last sentence of subsection (a) thereof is amended by
deleting the text "and (iii)" in such sentence; and

                  (e) by inserting a new subsection (d) thereto as follows: "(d)
Notwithstanding anything to the contrary in paragraph (a) hereof or in Section
5.02, the transfer of all or substantially all of the Company's assets
(determined on a consolidated basis for the Company and the Company's Restricted
Subsidiaries) whether as an entirety or substantially as an entirety to a Wholly
Owned Restricted Subsidiary of the Company shall be expressly permitted without
complying with the foregoing paragraph (a), and such Wholly Owned Restricted
Subsidiary of the Company shall not succeed to, or be substituted for, or
exercise any right or power of, the Company under this Indenture and shall not
be deemed a successor to the Company for any purpose under this Indenture."

1.15     AMENDMENT OF SECTION 6.01.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 6.01 of the Indenture are amended as follows:

                  (a) by deleting the text of each of subsections (c), (d) and
(e) in its entirety and inserting in lieu of each subsection the phrase
"[intentionally omitted]"; and

                  (b) by deleting the last paragraph of Section 6.01 in its
entirety.
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1.16     AMENDMENT OF SECTION 8.03.

         Effective upon, and subject only to, the Acceptance, the provisions of
Section 8.03 of the Indenture are amended by deleting the text of each of
subsections (b), (c), (d), (e), (f) and (h) in its entirety and inserting in
lieu of each subsection the phrase "[intentionally omitted]."

1.17     CONFORMING AMENDMENTS.

         Effective upon, and subject only to, the Acceptance, the form of
Security and the outstanding Securities are hereby amended to make any and all
changes that correspond to the amendments to the Indenture set forth in Sections
1.1 through 1.16 of this Second Supplemental Indenture.

                                   ARTICLE II

                                  MISCELLANEOUS

2.1      INTERPRETATION.

         Upon execution and delivery of this Second Supplemental Indenture, the
Indenture shall be modified and amended in accordance with this Second
Supplemental Indenture, and all the terms and conditions of both shall be read
together as though they constitute one instrument, except that, in case of
conflict, the provisions of this Second Supplemental Indenture will control. The
Indenture, as modified and amended by this Second Supplemental Indenture, is
hereby ratified and confirmed in all respects and shall bind every Holder of
Securities. In case of conflict between the terms and conditions contained in
the Securities and those contained in the Indenture, as modified and amended by
this Second Supplemental Indenture, the provisions of the Indenture, as modified
and amended by this Second Supplemental Indenture, shall control.

2.2      CONFLICT WITH TRUST INDENTURE ACT.

         If any provision of this Second Supplemental Indenture limits,
qualifies or conflicts with any provision of the Trust Indenture Act of 1939
(the "TIA") that is required under the TIA to be part of and govern any
provision of this Second Supplemental Indenture, the provision of the TIA shall
control. If any provision of this Second Supplemental Indenture modifies or
excludes any provision of the TIA that may be so modified or excluded, the
provision of the TIA shall be deemed to apply to the Indenture as so modified or
to be excluded by this Second Supplemental Indenture.

2.3      SEVERABILITY.

         In case any provision in this Second Supplemental Indenture shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be affected or impaired thereby.
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2.4      TERMS DEFINED IN THE INDENTURE.

         All capitalized terms not otherwise defined herein shall have the
meanings ascribed to them in the Indenture.

2.5      HEADINGS.

         The Article and Section headings of this Second Supplemental Indenture
have been inserted for convenience of reference only, are not to be considered a
part of this Second Supplemental Indenture and shall in no way modify or
restrict any of the terms or provisions hereof.

2.6      BENEFITS UNDER SECOND SUPPLEMENTAL INDENTURE, ETC.

         Nothing in this Second Supplemental Indenture or the Securities,
express or implied, shall give to any Person, other than the parties hereto and
thereto and their successors hereunder and thereunder and the Holders of the
Securities, any benefit of any legal or equitable right, remedy or claim under
the Indenture, this Second Supplemental Indenture or the Securities.

2.7      SUCCESSORS.

         All agreements of the Company and the Guarantors in this Second
Supplemental Indenture shall bind their respective successors. All agreements of
the Trustee in this Second Supplemental Indenture shall bind its successors.

2.8      THE TRUSTEE.

         The Trustee shall not be responsible in any manner whatsoever for or in
respect of the validity or sufficiency of this Second Supplemental Indenture or
for or in respect of the recitals contained herein, all of which are made solely
by the Company and the Guarantors.

2.9      CERTAIN DUTIES AND RESPONSIBILITIES OF THE TRUSTEE.

         In entering into this Second Supplemental Indenture, the Trustee shall
be entitled to the benefit of every provision of the Indenture relating to the
conduct or affecting the liability or affording protection to the Trustee,
whether or not elsewhere herein so provided.

2.10     GOVERNING LAW.

         THIS SECOND SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED
IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK AS APPLIED TO CONTRACTS
MADE AND PERFORMED WITHIN THE STATE OF NEW YORK, WITHOUT REGARD TO PRINCIPLES OF
CONFLICTS OF LAW. Each of the parties hereto agrees to submit to the
jurisdiction of the courts of the State of New York in any action or proceeding
arising out of or relating to this Second Supplemental Indenture.
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2.11     COUNTERPART ORIGINALS.

         The parties may sign any number of copies of this Second Supplemental
Indenture. Each signed copy shall be an original, but all of them together
represent one and the same agreement.

                            [signature pages follow]
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                  IN WITNESS WHEREOF, the parties hereto have caused this Second
Supplemental Indenture to be duly executed, all as of the date first above
written.

                                   QUALITY DISTRIBUTION, INC.



                                   By: /s/ Thomas L. Finkbiner
                                       Title:  President and
                                       Chief Executive Officer


                                   THE BANK OF NEW YORK,
                                        as Trustee



                                   By: /s/ Sirojni L. Dindial
                                       Title:  Assistant Vice President
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                                   GUARANTORS:

                                   AMERICAN TRANSINSURANCE GROUP, INC.
                                   CAPACITY MANAGEMENT SYSTEMS, INC.
                                   CHEMICAL LEAMAN CORPORATION
                                   CHEMICAL LEAMAN TANK LINES, INC.
                                   CHEMICAL PROPERTIES, INC.
                                   CLM, INC.
                                   CLT SERVICES, INC.
                                   ENVIROPOWER, INC.
                                   FLEET TRANSPORT COMPANY, INC.
                                   LAKESHORE LEASING, INC.
                                   LLI, INC.
                                   MEXICO INVESTMENTS, INC.
                                   PICKERING WAY FUNDING CORP.
                                   POWER PURCHASING, INC.
                                   QUALITY CARRIERS, INC.
                                   QSI SERVICES, INC.


                                   By: /s/ Thomas L. Finkbiner
                                       Title:    President

                                   QUALA SYSTEMS, INC.
                                   TRANSPLASTICS, INC.


                                   By: /s/ Dennis Farnsworth
                                       Title:    Vice President/Treasurer

                                   M T L OF NEVADA


                                   By: /s/ Leo Massey
                                       Title:    President