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                                                                     Exhibit 4.1

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                            7% SENIOR NOTES DUE 2003


                          ----------------------------


                          FIRST SUPPLEMENT TO INDENTURE

                            DATED AS OF MAY 31, 2001


                          ----------------------------


                       NAVISTAR INTERNATIONAL CORPORATION,
                                   AS ISSUER,

                   INTERNATIONAL TRUCK AND ENGINE CORPORATION,
                           AS A SUBSIDIARY GUARANTOR,

                                       AND

                           BNY MIDWEST TRUST COMPANY,
                                   AS TRUSTEE



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<PAGE>

                          FIRST SUPPLEMENT TO INDENTURE

         This First Supplement to Indenture is dated as of May 31, 2001 by and
among Navistar International Corporation, a Delaware corporation (the
"COMPANY"), International Truck and Engine Corporation, a Delaware corporation
("INTERNATIONAL"), and wholly owned subsidiary of the Company, and BNY Midwest
Trust Company, an Illinois banking corporation (the "TRUSTEE"), as successor to
Harris Trust and Savings Bank, with respect to the Company's 7% Senior Notes due
2003 (this "FIRST SUPPLEMENT"). Capitalized terms used but not otherwise defined
in this First Supplement shall have the meanings ascribed to such terms in the
Indenture (hereinafter defined).

         WHEREAS, the Company and the Trustee entered into that certain
Indenture, dated as February 4, 1998 (as may be amended and supplemented from
time to time in accordance with its terms, the "INDENTURE");

         WHEREAS, Section 4.15 of the Indenture requires that any Restricted
Subsidiary of the Company that guarantees any other indebtedness of the Company
simultaneously execute and deliver a supplemental indenture providing for the
guarantee of the payment of the Securities by such Restricted Subsidiary;

         WHEREAS, on the date hereof, the Company is issuing $400 million in
aggregate principal amount of 9 3/8% Senior Notes due 2006 (the "NEW NOTES")
under that certain Indenture, dated as of May 31, 2001, by and among the
Company, International and BNY Midwest Trust Company (the "NEW INDENTURE"), and
all of the obligations of the Company under the New Notes and the New Indenture
will be guaranteed by International; and

         WHEREAS, pursuant to Section 9.1 of the Indenture, the Trustee is
authorized to execute and deliver this First Supplemental.

         NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereby agree, for the equal and proportionate benefit
of all Holders of the Securities, as follows:

                                    ARTICLE I
                               SUBSIDIARY GUARANTY

         Section 1.01 INDENTURE AMENDMENT. The Indenture shall hereby be amended
and supplemented by incorporating the Guarantee of Securities set forth as
EXHIBIT A hereto into the Indenture as new Article XI thereto.

         Section 1.02 SUBSIDIARY GUARANTEE. International hereby agrees to
become subject to the terms of the Indenture as a Subsidiary Guarantor
thereunder and, to evidence such Subsidiary Guarantee, will execute and deliver
concurrently herewith a notation of guarantee substantially in the form attached
as EXHIBIT B hereto.


                                        1
<PAGE>

                                   ARTICLE II
                            MISCELLANEOUS PROVISIONS

         Section 2.01 INSTRUMENTS TO BE READ TOGETHER. This First Supplement is
an indenture supplement to and in implementation of the Indenture, and said
Indenture and this First Supplement shall henceforth be read together.

         Section 2.02 CONFIRMATION. The Indenture, as amended and supplemented
by this First Supplement, is in all respects confirmed and preserved.

         Section 2.03 COUNTERPARTS. This First Supplement may be executed in any
number of counterparts, each of which, when so executed, shall be deemed to be
an original, but all of which shall together constitute one and the same
instrument.

         Section 2.04 EFFECTIVENESS. This First Supplement shall become
effective immediately upon its execution in accordance with the provisions of
Article Nine of the Indenture.

         Section 2.05 GOVERNING LAW. THIS FIRST SUPPLEMENT AND THE SUBSIDIARY
GUARANTEE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE INTERNAL
LAWS OF THE STATE OF NEW YORK. THE COMPANY AND EACH SUBSIDIARY GUARANTOR AGREES
TO SUBMIT TO THE JURISDICTION OF THE COURTS OF THE STATE OF NEW YORK, COUNTY OF
NEW YORK, IN ANY ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO THIS FIRST
SUPPLEMENT AND THE SUBSIDIARY GUARANTEES.

        Section 2.06 DISCLAIMER OF TRUSTEE'S RESPONSIBILITY. In executing this
First Supplement, the Trustee shall be entitled to all the privileged and
immunities afforded to the Trustee under the terms and conditions of the
Indenture.

                                   *  *  *  *


                                        2
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        IN WITNESS WHEREOF, the parties hereto have caused this First Supplement
to Indenture to be duly executed as of the date first above written.

                                   NAVISTAR INTERNATIONAL CORPORATION


                                   By: /s/ T.M. Hough
                                       ----------------------------------
                                       Name:  Thomas M. Hough
                                       Title: Vice President and Treasurer


                                   INTERNATIONAL TRUCK AND ENGINE
                                   CORPORATION


                                   By: /s/ T.M. Hough
                                       ----------------------------------
                                       Name:  Thomas M. Hough
                                       Title: Vice President and Treasurer


                                   BNY MIDWEST TRUST COMPANY


                                   By: /s/ D.G. Donovan
                                       ------------------------------
                                       Name: D.G. Donovan
                                       Its:  Assistant Vice President


<PAGE>

                                                                       EXHIBIT A


                                   ARTICLE XI

                             GUARANTEE OF SECURITIES


        SECTION 11.1 SUBSIDIARY GUARANTEE.

               Subject to the provisions of this Article XI, each Subsidiary
Guarantor hereby jointly and severally unconditionally guarantees to each Holder
of a Security authenticated and delivered by the Trustee and to the Trustee and
its successors and assigns, irrespective of the validity and enforceability of
this Indenture, the Securities or the obligations of the Company or any other
Subsidiary Guarantors to the Holders or the Trustee hereunder or thereunder,
that: (a) the principal of, premium, if any, and interest on the Securities will
be duly and punctually paid in full when due, whether at maturity, by
acceleration or otherwise, and interest on the overdue principal and (to the
extent permitted by law) interest, if any, on the Securities and all other
obligations of the Company or the Subsidiary Guarantors to the Holders or the
Trustee hereunder or thereunder (including fees or expenses) and all other
obligations with respect to the Securities and this Indenture will be promptly
paid in full or performed, all in accordance with the terms hereof and thereof;
and (b) in case of any extension of time of payment or renewal of any
Securities, the same will be promptly paid in full when due or performed in
accordance with the terms of the extension or renewal, whether at Stated
Maturity, by acceleration or otherwise. Failing payment when due of any amount
so guaranteed, or failing performance of any other obligation of the Company to
the Holders, for whatever reason, each Subsidiary Guarantor will be obligated to
pay, or to perform or cause the performance of, the same immediately. An Event
of Default under this Indenture or the Securities shall constitute an event of
default under this Subsidiary Guarantee, and shall entitle the Holders of
Securities to accelerate the obligations of the Subsidiary Guarantors hereunder
in the same manner and to the same extent as the obligations of the Company.

               Each of the Subsidiary Guarantors hereby agrees that its
obligations hereunder shall be unconditional, irrespective of the validity,
regularity or enforceability of the Securities or this Indenture, the absence of
any action to enforce the same, any waiver or consent by any holder of the
Securities with respect to any provisions hereof or thereof, any release of any
other Subsidiary Guarantor, the recovery of any judgment against the Company,
any action to enforce the same, whether or not a Subsidiary Guarantee is affixed
to any particular Security, or any other circumstance which might otherwise
constitute a legal or equitable discharge or defense of a guarantor. Each of the
Subsidiary Guarantors hereby waives the benefit of diligence, presentment,
demand of payment, filing of claims with a court in the event of insolvency or
bankruptcy of the Company, any right to require a proceeding first against the
Company, protest, notice and all demands whatsoever and covenants that its
Subsidiary Guarantee will not be discharged except by complete performance of
the obligations contained in the Securities, this Indenture and this Subsidiary
Guarantee. If any


                                       A-1
<PAGE>

Holder or the Trustee is required by any court or otherwise to return to the
Company or to any Subsidiary Guarantor, or any custodian, trustee, liquidator or
other similar official acting in relation to the Company or such Subsidiary
Guarantor, any amount paid by the Company or such Subsidiary Guarantor to the
Trustee or such Holder, this Subsidiary Guarantee, to the extent theretofore
discharged, shall be reinstated in full force and effect. Each Subsidiary
Guarantor further agrees that, as between it, on the one hand, and the Holders
of Securities and the Trustee, on the other hand, (a) subject to this Article
XI, the maturity of the obligations guaranteed hereby may be accelerated as
provided in Article VI hereof for the purposes of this Subsidiary Guarantee,
notwithstanding any stay, injunction or other prohibition preventing such
acceleration in respect of the obligations guaranteed hereby, and (b) in the
event of any acceleration of such obligations as provided in Article VI hereof,
such obligations (whether or not due and payable) shall forthwith become due and
payable by the Subsidiary Guarantors for the purpose of this Subsidiary
Guarantee.

               This Subsidiary Guarantee shall remain in full force and effect
and continue to be effective should any petition be filed by or against the
Company for liquidation or reorganization, should the Company become insolvent
or make an assignment for the benefit of creditors or should a receiver or
trustee be appointed for all or any significant part of the Company's assets,
and shall, to the fullest extent permitted by law, continue to be effective or
be reinstated, as the case may be, if at any time payment and performance of the
Securities are, pursuant to applicable law, rescinded or reduced in amount, or
must otherwise be restored or returned by any obligee on the Securities, whether
as a "voidable preference," "fraudulent transfer" or otherwise, all as though
such payment or performance had not been made. In the event that any payment, or
any part thereof, is rescinded, reduced, restored or returned, the Securities
shall, to the fullest extent permitted by law, be reinstated and deemed reduced
only by such amount paid and not so rescinded, reduced, restored or returned.

               No stockholder, officer, director, employer or incorporator,
past, present or future, or any Subsidiary Guarantor, as such, shall have any
personal liability under this Subsidiary Guarantee by reason of his, her or its
status as such stockholder, officer, director, employer or incorporator.

               The Subsidiary Guarantors shall have the right to seek
contribution from any non-paying Subsidiary Guarantor so long as the exercise of
such right does not impair the rights of the Holders under this Subsidiary
Guarantee.

               Each Subsidiary Guarantor, and by its acceptance hereof each
Holder, hereby confirms that it is the intention of all such parties that the
guarantee by each Subsidiary Guarantor pursuant to its Subsidiary Guarantee not
constitute a fraudulent transfer or conveyance for purposes of the Bankruptcy
Law, the Uniform Fraudulent Conveyance Act, the Uniform Fraudulent Transfer Act
or any similar Federal or state law. To effectuate the foregoing intention, the
Holders and each Subsidiary Guarantor hereby irrevocably agrees that the
obligations of each Subsidiary Guarantor under the Subsidiary Guarantees shall
be limited to the maximum amount as will, after giving effect to all other
contingent and fixed liabilities of each Subsidiary Guarantor (including, but
not limited to, the Guarantor Senior Indebtedness of each Subsidiary Guarantor)
result in the obligations of each


                                       A-2
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Subsidiary Guarantor under the Subsidiary Guarantees not constituting such
fraudulent transfer or conveyance.

        SECTION 11.2 EXECUTION AND DELIVERY OF SUBSIDIARY GUARANTEE.

               To further evidence the Subsidiary Guarantee set forth in Section
11.1, each Subsidiary Guarantor hereby agrees that a notation of such Subsidiary
Guarantee, substantially in the form included in Exhibit C hereto, shall be
endorsed on each Security authenticated and delivered by the Trustee after such
Subsidiary Guarantee is executed and executed by either manual or facsimile
signature of an Officer of each Subsidiary Guarantor. The validity and
enforceability of any Subsidiary Guarantee shall not be affected by the fact
that it is not affixed to any particular Security.

               Each of the Subsidiary Guarantors hereby agrees that its
Subsidiary Guarantee set forth in Section 11.1 shall remain in full force and
effect notwithstanding any failure to endorse on each Security a notation of
such Subsidiary Guarantee.

               If an Officer of a Subsidiary Guarantor whose signature is on
this Indenture or a Security no longer holds that office at the time the Trustee
authenticates such Security or at any time thereafter, such Subsidiary
Guarantor's Subsidiary Guarantee of such Security shall be valid nevertheless.

               The delivery of any Security by the Trustee, after the
authentication thereof hereunder, shall constitute due delivery of any
Subsidiary Guarantee set forth in this Indenture on behalf of the Subsidiary
Guarantor.

        SECTION 11.3  ADDITIONAL SUBSIDIARY GUARANTORS.

               Any person may become a Subsidiary Guarantor by executing and
delivering to the Trustee (a) a supplemental indenture in form and substance
satisfactory to the Trustee, which subjects such person to the provisions of
this Indenture as a Subsidiary Guarantor, and (b) an Opinion of Counsel to the
effect that such supplemental indenture has been duly authorized and executed by
such person and constitutes the legal, valid, binding and enforceable obligation
of such person (subject to such customary exceptions concerning fraudulent
conveyance laws, creditors' rights and equitable principles as may be acceptable
to the Trustee in its discretion).

        SECTION 11.4 RELEASE OF A SUBSIDIARY GUARANTOR.

               (a) In the event that each other holder of Indebtedness of the
Company or of any of the Company's Subsidiaries of which a Subsidiary Guarantor
has guaranteed the payment thereof unconditionally releases a Subsidiary
Guarantor of all of its obligations under such guarantee pursuant to a written
agreement in form and substance satisfactory to the Trustee (other than a
release resulting from payment under such guarantee) such Subsidiary Guarantor
shall be automatically and unconditionally released from all obligations under
its Subsidiary Guarantee,


                                       A-3
<PAGE>

PROVIDED that a release of a Subsidiary Guarantor may only be obtained under the
circumstances described in this sentence if an Officers' Certificate to that
effect has been delivered to the Trustee.

               (b) In addition, except in the case where the prohibition on
transfer in Section 5.1 is applicable, upon the sale or disposition of all (but
not less than all) of the Capital Stock of a Subsidiary Guarantor by the Company
or a Subsidiary of the Company, or upon the consolidation or merger of a
Subsidiary Guarantor with or into any Person (in each case, other than to the
Company or an Affiliate of the Company), such Subsidiary Guarantor shall be
deemed automatically and unconditionally released and discharged from all
obligations under this Article XI without any further action required on the
part of the Trustee or any Holder, PROVIDED that each such Subsidiary Guarantor
is sold or disposed of in accordance with Article V.

               (c) The Trustee shall deliver an appropriate instrument
evidencing the release of a Subsidiary Guarantor upon receipt of a request of
the Company accompanied by an Officers' Certificate certifying as to the
compliance with this Section 11.4. Any Subsidiary Guarantor not so released or
the entity surviving such Subsidiary Guarantor, as applicable, will remain or be
liable under its Subsidiary Guarantee as provided in this Article XI.

               The Trustee shall execute any documents reasonably requested by
the Company or a Subsidiary Guarantor in order to evidence the release of such
Subsidiary Guarantor from its obligations under its Subsidiary Guarantee
endorsed on the Securities and under this Article XI.

               Except as set forth in Articles IV and V and this Section 11.4,
nothing contained in this Indenture or in any of the Securities shall prevent
any consolidation or merger of a Subsidiary Guarantor with or into the Company
or another Subsidiary Guarantor or shall prevent any sale or conveyance of the
property of a Subsidiary Guarantor as an entirety or substantially as an
entirety to the Company or another Subsidiary Guarantor.

        SECTION 11.5 RELATIVE RIGHTS.

               Nothing contained in this Article XI or elsewhere in this
Indenture or in the Securities or this Subsidiary Guarantee is intended to or
shall impair, as between the Subsidiary Guarantor, its creditors, and the
holders of its Subsidiary Guarantee, the obligation of such Subsidiary
Guarantor, which is absolute and unconditional, to pay to the holders of the
Securities pursuant to its Subsidiary Guarantee the principal of and interest on
the Securities as and when the same shall become due and payable in accordance
with their terms, or is intended to or shall affect the relative rights of the
holders of its Subsidiary Guarantee and creditors of such Subsidiary Guarantor,
nor shall anything herein or therein prevent the Trustee or any holder of its
Subsidiary Guarantee from exercising all remedies otherwise permitted by
applicable law upon default under this Indenture.

               Upon payment or distribution of assets of such Subsidiary
Guarantor referred to in this Article XI, the Trustee and the holders of the
Securities shall be entitled to rely upon any order or decree made by any court
of competent jurisdiction in which any such dissolution, winding up,


                                       A-4
<PAGE>

liquidation or reorganization proceeding affecting the affairs of such
Subsidiary Guarantor is pending or upon a certificate of the trustee in
bankruptcy, receiver, assignee for the benefit of creditors, liquidating
trustee, or agent or other person making any payment or distribution, to the
Trustee or to the holders of its Subsidiary Guarantee for the purpose of
ascertaining the persons entitled to participate in such payment or
distribution, and other indebtedness of such Subsidiary Guarantor, the amount
thereof or payable thereon, the amount paid or distributed thereon and all other
facts pertinent thereto or to this Article XI.

               Nothing contained in this Article or elsewhere in this Indenture,
or in any of the Securities or this Subsidiary Guarantee, shall affect the
obligations of such Subsidiary Guarantor to make, or prevent such Subsidiary
Guarantor from making, payment of the principal of or interest on the Securities
pursuant to its Subsidiary Guarantee in accordance with the provisions hereof
and thereof, except as otherwise provided in this Article XI.


                                       A-5
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                                                                       EXHIBIT B

                                    GUARANTEE

        For value received, the undersigned hereby unconditionally guarantees to
the Holder of this Security the payments of principal of, premium, if any, and
interest on this Security in the amounts and at the time when due and interest
on the overdue principal, premium, if any, and interest, if any, of this
Security, if lawful, and the payment or performance of all other obligations of
the Company under the Indenture or the Securities, to the Holder of this
Security and the Trustee, all in accordance with and subject to the terms and
limitations of this Security, Article XI of the Indenture and this Subsidiary
Guarantee. This Subsidiary Guarantee will become effective in accordance with
Article XI of the Indenture and its terms shall be evidenced therein. The
validity and enforceability of any Subsidiary Guarantee shall not be affected by
the fact that it is not affixed to any particular Security.

        The obligations of the undersigned to the Holders of Securities and to
the Trustee pursuant to the Subsidiary Guarantee and the Indenture are expressly
set forth in Article XI of the Indenture and reference is hereby made to the
Indenture for the precise terms of the Subsidiary Guarantee and all of the other
provisions of the Indenture to which this Subsidiary Guarantee relates. Each
Holder of a Security, by accepting the same, (a) agrees to and shall be bound by
such provisions, and (b) appoints the Trustee attorney-in-fact of such Holder
for such purpose.

        This Subsidiary Guarantee is subject to release upon the terms set forth
in the Indenture.

                                             INTERNATIONAL TRUCK AND ENGINE
                                             CORPORATION


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


                                       B-1
<PAGE>

                                                                       EXHIBIT C

                                    GUARANTEE

        For value received, the undersigned hereby unconditionally guarantees to
the Holder of this Security the payments of principal of, premium, if any, and
interest on this Security in the amounts and at the time when due and interest
on the overdue principal, premium, if any, and interest, if any, of this
Security, if lawful, and the payment or performance of all other obligations of
the Company under the Indenture or the Securities, to the Holder of this
Security and the Trustee, all in accordance with and subject to the terms and
limitations of this Security, Article XI of the Indenture and this Subsidiary
Guarantee. This Subsidiary Guarantee will become effective in accordance with
Article XI of the Indenture and its terms shall be evidenced therein. The
validity and enforceability of any Subsidiary Guarantee shall not be affected by
the fact that it is not affixed to any particular Security.

        The obligations of the undersigned to the Holders of Securities and to
the Trustee pursuant to the Subsidiary Guarantee and the Indenture are expressly
set forth in Article XI of the Indenture and reference is hereby made to the
Indenture for the precise terms of the Subsidiary Guarantee and all of the other
provisions of the Indenture to which this Subsidiary Guarantee relates. Each
Holder of a Security, by accepting the same, (a) agrees to and shall be bound by
such provisions, and (b) appoints the Trustee attorney-in-fact of such Holder
for such purpose.

        This Subsidiary Guarantee is subject to release upon the terms set forth
in the Indenture.

                                             [NAME OF GUARANTOR]


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


                                       C-1