Exhibit 10.1

Execution Version

July 31, 2012

Navistar International Corporation

2701 Navistar Drive

Lisle, IL 60532

Attention: Jim Moran

Navistar International Corporation/Navistar, Inc.

Commitment Letter

Ladies and Gentlemen:

You have advised JPMorgan Chase Bank, N.A. (“JPMorgan Chase Bank”), J.P. Morgan Securities LLC (“JPMorgan”) and Goldman Sachs Lending Partners LLC (“Goldman Sachs”, and together with JPMorgan Chase Bank and JPMorgan, the “Commitment Parties”, “us” or “we”) that Navistar International Corporation, a Delaware corporation (“Parent”), and Navistar, Inc., a Delaware corporation and a wholly owned subsidiary of Parent (the “Borrower” and, together with Parent, “you”), would like (i) JPMorgan and Goldman Sachs to act as lead arrangers and bookrunners (acting in such capacities, the “Lead Arrangers”) in connection with, (ii) JPMorgan Chase Bank and Goldman Sachs to commit to provide the financing for (acting in such capacities, the “Initial Lenders”) and (iii) JPMorgan Chase Bank to act as administrative agent for, the senior secured credit facility described herein (the “Facility”), in each case on the terms and subject to the conditions set forth in this letter and the attached Exhibits A and B hereto (such Exhibits (collectively, the “Term Sheet”), together with this letter and Exhibit C, collectively, as amended, modified or supplemented from time to time, the “Commitment Letter”). Capitalized terms used but not defined in this letter are used with the meanings assigned to them in the Exhibits attached hereto.

1. Commitments

Each Initial Lender is pleased to advise you of its commitment, severally and not jointly, to provide 50% of the amount of the Facility upon the terms and subject solely to the conditions set forth or expressly referred to in this letter and the Term Sheet.

In addition, if the amendment to the Existing ABL Credit Agreement conforms to the requirements set forth in paragraph 1 of Exhibit B and is otherwise in form and substance reasonably satisfactory to JPMorgan Chase Bank, JPMorgan Chase Bank will consent to such amendment in connection with the initial funding under the Facility.

2. Titles and Roles

It is agreed that (i) the Lead Arrangers will act as lead arrangers and bookrunners for the Facility, (ii) JPMorgan Chase Bank will act as sole administrative agent for the Facility and (iii) Goldman Sachs will act as syndication agent for the Facility.

It is further agreed that JPMorgan will have “left” placement in any marketing materials or other documentation used in connection with the Facility. Except as otherwise provided herein, you agree that no other agents, co-agents, arrangers, co-arrangers, bookrunners, co-bookrunners, managers or co-managers will be appointed, no other titles will be awarded and no compensation (other than that expressly contemplated by the Term Sheet and Fee Letters referred to below) will be paid in connection with the Facility unless you and we shall so reasonably agree (it being understood and agreed that no other agent, co-agent, arranger, co-arranger, bookrunner, co-bookrunner, manager or co-manager shall be entitled to greater economics in respect of the Facility than the Commitment Parties). It is understood that you shall have the right to appoint, with up to 40% of the economics and commitment amounts for the Facility, up to 2 additional financial institutions as bookrunners and up to an additional 3 financial institutions as co-agents or co-managers (or such other number of financial institutions as mutually agreed) (the “Additional Lenders”); provided that any such institution has provided its commitment to the Facility no later than the earlier of the public announcement of the Facility or 5 p.m., New York City time, on August 1, 2012. The commitments of the Initial Lenders hereunder shall be reduced on a pro rata basis as and when corresponding commitments with respect to the Facility have been received from the Additional Lenders.

3. Syndication

We intend to syndicate the Facility to a group of lenders (other than Disqualified Lenders) identified by us in consultation with you (together with the Initial Lenders, the “Lenders”). The Commitment Parties intend to commence syndication efforts promptly, and you agree actively to assist the Commitment Parties in completing a syndication reasonably satisfactory to the Commitment Parties and you. Such assistance shall include (A) your using commercially reasonable efforts to ensure that the syndication efforts benefit from your existing banking relationships, (B) direct contact between your senior management and advisors and the proposed Lenders, (C) your preparing and providing to the Commitment Parties all customary or reasonably available or producible information with respect to you and your subsidiaries, including all customary financial information, Projections (as defined below), and collateral-related information, as the Commitment Parties may reasonably request in connection with the arrangement and syndication of the Facility and your assistance in the preparation of one or more confidential information memoranda (each, a “Confidential Information Memorandum”) and other customary marketing materials to be used in connection with the syndication (all such information, memoranda and material, “Information Materials”), (D) your hosting, with the Commitment Parties, of one meeting of prospective Lenders at a time and location to be mutually agreed (and additional teleconference calls as reasonably requested), (E) your using your commercially reasonable efforts to obtain ratings for the Facility from each of Moody’s Investors Service, Inc. (“Moody’s”) and Standard & Poor’s Financial Services LLC (“S&P”) as soon as practicable, and (F) your ensuring that, until the earlier of achieving a Successful Syndication (as defined in the Syndication Fee Letter) and 60 days following the Closing Date, there is no competing offering, placement, arrangement or syndication of any debt securities or bank financing or announcement thereof by or on behalf of you or your domestic Restricted Subsidiaries (other than (i) the Facility or any refinancing thereof, (ii) any amendment of the Existing ABL Credit Agreement, so long as such amendment is consistent with the provisions of Exhibit B attached hereto, (iii) debt disclosed to the Lead Arrangers on or prior to the date hereof and (iv) debt incurred in the ordinary course of business). Without limiting your obligations to assist with syndication efforts as set forth above, notwithstanding anything to the contrary contained in this Commitment Letter or the Fee Letters or any other letter agreement or undertaking concerning the financing of the transactions to the contrary, each

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Commitment Party agrees that, so long as the conditions set forth in Section 6 of this Commitment Letter and in the Term Sheet are satisfied (or, as the case may be, waived), neither the commencement nor completion of such syndication, nor the obtaining of the ratings referenced above, is a condition to its commitments hereunder or the initial funding of the Facility on the Closing Date.

The Commitment Parties will manage, in consultation with you, all aspects of the syndication, including decisions as to the selection of institutions (other than Disqualified Lenders) to be approached and when they will be approached, when commitments will be accepted, which institutions will participate, the allocation of the commitments among the Lenders and the amount and distribution of fees among the Lenders; provided, that notwithstanding the Commitment Parties’ right to syndicate the Facility and receive commitments with respect thereto, (i) no Initial Lender shall be relieved, released or novated from its obligations hereunder (including its obligation to fund the Facility on the Closing Date in accordance with the terms and conditions of this Commitment Letter) in connection with any syndication, assignment or participation of the Facility (other than assignment to Additional Lenders), including its commitment in respect thereof, until after the Closing Date has occurred, (ii) no assignment or novation by any Initial Lender (other than assignment or novation to Additional Lenders) shall become effective as between you and such Initial Lender with respect to all or any portion of such Initial Lender’s commitment in respect of the Facility until the initial funding of the Facility and (iii) unless you otherwise agree in writing, each Initial Lender shall retain exclusive control over all rights and obligations with respect to its commitment in respect of the Facility (other than commitments reduced pursuant to the accession of the Additional Lenders), including all rights with respect to consents, modifications, supplements, waivers and amendments, until the Closing Date has occurred. In no event shall the Commitment Parties be subject to any fiduciary or other implied duties in connection with the transactions contemplated hereby.

At the request of the Commitment Parties, you agree to assist in the preparation of a version of each Confidential Information Memorandum or other Information Material (a “Public Version”) consisting exclusively of information with respect to you and your subsidiaries that is either publicly available or not material with respect to you and your subsidiaries or any of your securities for purposes of United States federal and state securities laws (such information, “Non-MNPI”). Such Public Version, together with any other information prepared by you or your subsidiaries or representatives and conspicuously marked “Public” (collectively, the “Public Information”), which at a minimum means that the word “Public” will appear prominently on the first page of any such information, may be distributed by us to prospective Lenders who have advised us that they wish to receive only Non-MNPI (“Public Side Lenders”). You acknowledge and agree that, in addition to Public Information, (a) drafts and final definitive documentation with respect to the Facility (other than schedules identified by you), (b) administrative materials prepared by the Commitment Parties for prospective Lenders (such as a lender meeting invitation, allocations and funding and closing memoranda), (c) certain information related to collateral or guarantors (including information to be attached hereto as Exhibit C, the contents of which shall be reasonably satisfactory to the Arrangers and the Delaware opinion referenced in paragraph 3 of Exhibit B) and (d) notifications of changes in the terms of the Facility may be distributed to Public Side Lenders. You acknowledge that Commitment Party public-side employees and representatives who are publishing debt analysts may participate in any meetings held pursuant to clause (D) of the second preceding paragraph; provided that such analysts shall not publish any information obtained from such meetings (i) until the syndication of the Facility has been completed upon the making of allocations by the Lead Arrangers and the Lead Arrangers freeing the Facility to trade or (ii) in violation of any confidentiality agreement between you and the relevant Commitment Party.

In connection with our distribution to prospective Lenders of any Confidential Information Memorandum and, promptly following our request, any other Information Materials, you will execute and deliver to us a customary authorization letter authorizing such distribution and, in the case of any Public Version thereof or other Public Information, representing that, as of the date of distribution, it only contains Non-MNPI. Each Confidential Information Memorandum will be accompanied by a disclaimer exculpating you and us with respect to any use thereof and of any related Information Materials by the recipients thereof.

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4. Information

You hereby represent and warrant that (a) all written information (including all Information Materials), other than the Projections, budgets, estimates and information of a general economic or industry specific nature (the “Information”), that has been or will be made available to us by you or any of your representatives in connection with the transactions contemplated hereby, when taken as a whole and as supplemented, does not or will not, when furnished to us, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements contained therein not materially misleading in light of the circumstances under which such statements are made (giving effect to all supplements thereto) and (b) the financial projections and other forward-looking information about you and your subsidiaries (the “Projections”), budgets and estimates that have been or will be made available to us by you or any of your representatives in connection with the transactions contemplated hereby have been or will be prepared in good faith based upon assumptions believed by you to be reasonable at the time furnished to us (it being recognized by the Commitment Parties that such Projections, budgets and estimates are not to be viewed as a guarantee of performance or facts and that actual results during the period or periods covered by any such Projections may differ from the projected results, and such differences may be material). You agree that if, at any time until the earlier of achieving a Successful Syndication and 60 days following the Closing Date, you become aware that any of the representations in the preceding sentence would be incorrect, in any material respect if the same were remade, then you will promptly supplement the Information and the Projections so that such representations when remade would be correct, in all material respects, under those circumstances. You understand that in arranging and syndicating the Facility we may use and rely on the Information and Projections without independent verification thereof.

5. Fees

As consideration for the commitments and agreements of the Commitment Parties hereunder, you agree to pay or cause to be paid the nonrefundable fees described in the (i) fee letter dated the date hereof and delivered herewith by the Commitment Parties to you (the “Syndication Fee Letter”), (ii) fee letter dated the date hereof and delivered herewith by the Commitment Parties to you relating to the arrangement of the Facilities (the “Arranger Fee Letter”) and (iii) fee letter dated the date hereof and delivered herewith by JPMorgan Chase Bank to you (the “Administrative Agent Fee Letter” and together with the Syndication Fee Letter and the Arranger Fee Letter, the “Fee Letters”) on the terms and subject to the conditions set forth therein.

6. Conditions

Each Commitment Party’s commitments and agreements hereunder are subject to the express conditions set forth in this Section 6 and in the Term Sheet.

Each Commitment Party’s commitments and agreements hereunder are further subject to (a) since the date hereof, there not having been any change, development or event that, individually or in the aggregate, has had or would reasonably be expected to have a material adverse effect on the business, financial condition, or results of operations of Parent and its subsidiaries, taken as a whole other than in respect of Excluded Matters, (b) such Commitment Party’s not becoming aware after the date hereof of any information or other matter (including any matter relating to assumptions for the Projections) affecting Parent or its subsidiaries that is inconsistent in a material and adverse manner with any such information or other matter of which such Commitment Party was aware prior to the date hereof or could reasonably be

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expected to materially impair the syndication of the Facility and (c) your performance in all material respects of all your obligations hereunder and under the Fee Letters. “Excluded Matters” means (i) any regulatory action by the U.S. Environmental Protection Agency (the “EPA”) or the California Air Resources Board (“CARB”) with respect to the NOx emissions standards for the 15L and 13L heavy-duty diesel engines (including, without limitation, any such action resulting from the decision of the United States Court of Appeals for the District of Columbia Circuit in Mack Trucks, Inc. and Volvo Group North America, LLC v. Environmental Protection Agency decided June 12, 2012) and events and conditions arising in connection therewith (the “Regulatory Actions”) but only so long as, notwithstanding any such Regulatory Actions, Parent and its subsidiaries shall (at all times on and after the date hereof and, in the case of the 15L heavy-duty diesel engines, prior to Parent and its subsidiaries commencing to sell trucks in the United States containing 15L heavy-duty diesel engines purchased from Cummins Inc. (“Cummins”) that have been certified by the EPA as complying with the NOx emissions standards for the 15L heavy-duty diesel engines and, in the case of the 13L heavy-duty diesel engines, prior to Parent and its subsidiaries having developed a 13L heavy-duty ICT+ diesel engine and such engine having been certified by the EPA as complying with the NOx emissions standards for the 13L heavy-duty diesel engines) be permitted to sell noncompliant 15L and 13L heavy-duty diesel engines (and trucks containing such engines) in the United States) and (ii) any adverse effect on the general affairs, assets, liabilities, financial position or results of operations of Parent and its subsidiaries, taken as a whole, on account of or related to the Regulatory Actions.

7. Indemnification and Expenses

You agree (a) to indemnify and hold harmless the Commitment Parties, their affiliates and their respective directors, officers, employees, advisors, agents and other representatives (each, an “indemnified person”) from and against any and all actual losses, claims, damages and liabilities to which any such indemnified person may become subject arising out of or in connection with this Commitment Letter, the Fee Letters, the Facility or the use of the proceeds thereof or any claim, litigation, investigation or proceeding (a “Proceeding”) relating to any of the foregoing, regardless of whether any indemnified person is a party thereto, whether or not such Proceedings are brought by you, your equity holders, affiliates, creditors or any other person, and to reimburse each indemnified person promptly following written demand (including documentation reasonably supporting such request) for any reasonable legal or other out-of-pocket expenses incurred in connection with investigating or defending any of the foregoing, provided that the foregoing indemnity will not, as to any indemnified person, apply to losses, claims, damages, liabilities or related expenses to the extent they are found by a final, nonappealable judgment of a court of competent jurisdiction to arise from (i) the willful misconduct or gross negligence of such indemnified person or its directors, officers or employees (collectively, the “Related Parties”) or (ii) from a material breach in bad faith of the obligations of such indemnified person (or its Related Parties) under this Commitment Letter, and (b) regardless of whether the Closing Date occurs, to reimburse each Commitment Party and its affiliates for all reasonable out-of-pocket expenses that have been invoiced prior to the Closing Date or following termination or expiration of the commitments hereunder (including reasonable due diligence expenses, syndication expenses, travel expenses, and the reasonable fees, charges and disbursements of counsel) incurred in connection with the Facility and any related documentation (including this Commitment Letter and the definitive financing documentation) or the administration, amendment, modification or waiver thereof. It is further agreed that each Commitment Party shall only have liability to you (as opposed to any other person) and that each Commitment Party shall be liable solely in respect of its own commitment to the Facility on a several, and not joint, basis with any other Commitment Party. No indemnified person shall be liable for any damages arising from the use by others of Information or other materials obtained through electronic, telecommunications or other information transmission systems, except to the extent any such damages are found by a final, nonappealable judgment of a court of competent jurisdiction to arise from the gross negligence, material breach or willful misconduct of such indemnified person (or any of its Related Parties). None of the indemnified persons or

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you, or any of your or their respective affiliates or the respective directors, officers, employees, advisors, and agents of the foregoing shall be liable for any indirect, special, punitive or consequential damages in connection with this Commitment Letter, the Fee Letters, the Facility or the transactions contemplated hereby, provided that nothing contained in this sentence shall limit your indemnity obligations to the extent set forth in this Section 7.

8. Sharing of Information, Absence of Fiduciary Relationship, Affiliate Activities

You acknowledge that each Commitment Party (or an affiliate) is a full service securities firm and such person may from time to time effect transactions, for its own or its affiliates’ account or the account of customers, and hold positions in loans, securities or options on loans or securities of you, your affiliates and of other companies that may be the subject of the transactions contemplated by this Commitment Letter. In addition, each Commitment Party and its affiliates will not use confidential information obtained from you or your affiliates or on your or their behalf by virtue of the transactions contemplated hereby in connection with the performance by such Commitment Party and its affiliates of services for other companies or persons and the Commitment Party and its affiliates will not furnish any such information to any of their other customers. You also acknowledge that the Commitment Parties and their respective affiliates have no obligation to use in connection with the transactions contemplated hereby, or to furnish to you, confidential information obtained from other companies or persons.

You further acknowledge and agree that (a) no fiduciary, advisory or agency relationship between you and the Commitment Parties is intended to be or has been created in respect of any of the transactions contemplated by this Commitment Letter, irrespective of whether the Commitment Parties have advised or are advising you on other matters, (b) the Commitment Parties, on the one hand, and you, on the other hand, have an arm’s length business relationship that does not directly or indirectly give rise to, nor do you rely on, any fiduciary duty to you or your affiliates on the part of the Commitment Parties as a result of the transactions contemplated by this commitment letter, (c) you are capable of evaluating and understanding, and you understand and accept, the terms, risks and conditions of the transactions contemplated by this Commitment Letter, (d) you have been advised that the Commitment Parties are engaged in a broad range of transactions that may involve interests that differ from your interests and that the Commitment Parties have no obligation to disclose such interests and transactions to you, (e) you have consulted your own legal, accounting, regulatory and tax advisors to the extent you have deemed appropriate, (f) each Commitment Party has been, is, and will be acting solely as a principal and, except as otherwise expressly agreed in writing by it and the relevant parties, has not been, is not, and will not be acting as an advisor, agent or fiduciary for you, any of your affiliates and (g) none of the Commitment Parties has any obligation to you or your affiliates with respect to the transactions contemplated hereby except those obligations expressly set forth herein or in any other express writing executed and delivered by such Commitment Party and you or any such affiliate.

9. Confidentiality

This Commitment Letter is delivered to you on the understanding that neither this Commitment Letter nor the Fee Letters nor any of their terms or substance shall be disclosed by you, to any other person except (a) you and your officers, directors, employees, affiliates, members, partners, attorneys, accountants, agents and advisors, in each case on a confidential and need-to-know basis, (b) in any legal, judicial or administrative proceeding or as otherwise required by law or regulation or as requested by a governmental authority (in which case you agree, to the extent permitted by law, to inform us promptly in advance thereof), (c) this Commitment Letter and the existence and contents hereof (but not the Fee Letters or the contents thereof other than the existence thereof and the contents thereof as part of projections, pro forma information and a generic disclosure of aggregate sources and uses to the extent customary in marketing materials and other required filings) may be disclosed in any syndication or other marketing material in connection with the Facility or in connection with any public filing requirement, (d) the Term Sheet may be disclosed to potential Lenders and to any rating agency in connection with the Facility and (e) in connection with any remedy or enforcement of any right under this Commitment Letter.

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The Commitment Parties shall use all nonpublic information received by them in connection with the Facility solely for the purposes of providing the services that are the subject of this Commitment Letter and shall treat confidentially all such information; provided, however, that nothing herein shall prevent any Commitment Party from disclosing any such information (a) to rating agencies, (b) to any Lenders or participants or prospective Lenders or participants (other than Disqualified Lenders), (c) in any legal, judicial, administrative proceeding or other compulsory process or as required by applicable law or regulations (in which case such Commitment Party shall promptly notify you, in advance, to the extent permitted by law), (d) upon the request or demand of any regulatory authority having jurisdiction over such Commitment Party or its affiliates, (e) to the employees, legal counsel, independent auditors, professionals and other experts or agents of such Commitment Party (collectively, “Representatives”) on a “need to know” basis who are informed of the confidential nature of such information and are or have been advised of their obligation to keep information of this type confidential, (f) to any of its respective affiliates (provided that any such affiliate is advised of its obligation to retain such information as confidential, and such Commitment Party shall be responsible for its controlled affiliates’ compliance with this paragraph) solely in connection with the Facility and any related transactions, (g) to the extent any such information becomes publicly available other than by reason of disclosure by such Commitment Party, its affiliates or Representatives in breach of this Commitment Letter or other confidentiality obligations owed to you or your affiliates and (h) for purposes of establishing a “due diligence” defense or in connection with any remedy or enforcement of any right under this Commitment Letter or the Fee Letters; provided that the disclosure of any such information to any Lenders or prospective Lenders or participants or prospective participants referred to above shall be made subject to the acknowledgment and acceptance by such Lender or prospective Lender or participant or prospective participant that such information is being disseminated on a confidential basis in accordance with standard syndication processes of such Commitment Party or customary market standards for dissemination of such type of information. The provisions of this paragraph shall automatically terminate one year following the date of this Commitment Letter.

10. Miscellaneous

This Commitment Letter shall not be assignable by you without the prior written consent of each Commitment Party (and any purported assignment without such consent shall be null and void), is intended to be solely for the benefit of the parties hereto and the indemnified persons and is not intended to and does not confer any benefits upon, or create any rights in favor of, any person other than the parties hereto and the indemnified persons to the extent expressly set forth herein. The Commitment Parties reserve the right to employ the services of their affiliates in providing services contemplated hereby and to allocate, in whole or in part, to their affiliates certain fees payable to the Commitment Parties in such manner as the Commitment Parties and their affiliates may agree in their sole discretion. This Commitment Letter may not be amended or waived except by an instrument in writing signed by you and each Commitment Party. This Commitment Letter may be executed in any number of counterparts, each of which shall be an original, and all of which, when taken together, shall constitute one agreement. Delivery of an executed signature page of this Commitment Letter by facsimile or electronic transmission (e.g., “pdf” or “tif”) shall be effective as delivery of a manually executed counterpart hereof. This Commitment Letter and the Fee Letters are the only agreements that have been entered into among us and you with respect to the Facility and set forth the entire understanding of the parties with respect thereto. This Commitment Letter and any claim or controversy arising hereunder or related hereto shall be governed by, and construed and interpreted in accordance with, the laws of the State of New York.

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You and we hereby irrevocably and unconditionally submit to the exclusive jurisdiction of any state or Federal court sitting in the Borough of Manhattan in the City of New York over any suit, action or proceeding arising out of or relating to the transactions contemplated hereby, this Commitment Letter or the Fee Letters or the performance of services hereunder or thereunder. You and we agree that service of any process, summons, notice or document by registered mail addressed to you or us shall be effective service of process for any suit, action or proceeding brought in any such court. You and we hereby irrevocably and unconditionally waive (to the extent permitted by applicable law) any objection to the laying of venue of any such suit, action or proceeding brought in any such court and any claim that any such suit, action or proceeding has been brought in any inconvenient forum. You and we hereby irrevocably waive (to the extent permitted by applicable law) trial by jury in any suit, action, proceeding, claim or counterclaim brought by or on behalf of any party related to or arising out of the transactions contemplated hereby, this Commitment Letter or the Fee Letters or the performance of services hereunder or thereunder.

Each of the Commitment Parties hereby notifies you that, pursuant to the requirements of the USA PATRIOT Act, Title III of Pub. L. 107-56 (signed into law on October 26, 2001) (the “PATRIOT Act”), it is required to obtain, verify and record information that identifies the Borrower and each Guarantor, which information includes names, addresses, tax identification numbers and other information that will allow such Lender to identify the Borrower and each Guarantor in accordance with the PATRIOT Act. This notice is given in accordance with the requirements of the PATRIOT Act and is effective for the Commitment Parties and each Lender.

The indemnification, expense, choice of law, jurisdiction, waiver of jury trial, syndication and confidentiality provisions contained herein and in the Fee Letters shall remain in full force and effect regardless of whether definitive financing documentation shall be executed and delivered and notwithstanding the termination of this Commitment Letter or the commitments hereunder; provided that your obligations under this Commitment Letter (other than your obligations with respect to (a) assistance to be provided in connection with the syndication thereof (including as to the provision of information and representations with respect thereto) and (b) confidentiality) shall automatically terminate and be superseded, to the extent comparable, by the provisions of the Facility Documentation upon the initial funding thereunder, and you shall automatically be released from all liability in connection therewith at such time, in each case to the extent the Facility Documentation has comparable provisions with comparable coverage. You may terminate this Commitment Letter and the Fee Letters by written notice to the Commitment Parties.

If the foregoing correctly sets forth our agreement, please indicate your acceptance of the terms of this Commitment Letter and the Fee Letters by returning to us executed counterparts of this Commitment Letter and the Fee Letters not later than 5:00 p.m., New York City time, on July 31, 2012. This offer will automatically expire at such time if we have not received (i) such executed counterparts in accordance with the preceding sentence and (ii) fees contemplated by the Syndication Fee Letter and the Arranger Fee Letter due and payable to the Arrangers on the date hereof. In the event that you and the Lenders have not entered into a definitive credit agreement in respect of the Facility on or before September 15, 2012, then this Commitment Letter and the commitments hereunder shall automatically terminate unless we shall, in our discretion, agree to an extension.

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We are pleased to have been given the opportunity to assist you in connection with this important financing.

Commitment Letter Signature Page

Accepted and agreed to as of the date first written above:

Commitment Letter Signature Page

EXECUTION VERSION

EXHIBIT A

CONFIDENTIAL

Navistar International Corporation

Navistar, Inc.

$1,000,000,000 Senior Secured Term Loan

Summary of Principal Terms and Conditions

This Summary outlines certain terms of the Facility referred to in the Commitment Letter, of which this Exhibit A is a part.

Exhibit A-1

Exhibit A-2

Exhibit A-3

Exhibit A-4

Exhibit A-5

Exhibit A-6

Exhibit A-7

Exhibit A-8

Exhibit A-9

Exhibit A-10

Exhibit A-11

Exhibit A-12

Exhibit A-13

EXHIBIT B

CONFIDENTIAL

Navistar International Corporation

Navistar, Inc.

$1,000,000,000 Senior Secured Term Loan

Summary of Conditions Precedent to the Facility

This Summary of Conditions Precedent outlines certain of the conditions precedent to the Facility referred to in the term sheet to which this Exhibit B is attached. Capitalized terms used but not defined herein shall have the meanings given to them in the term sheet.

Exhibit B-1

Exhibit B-2

satisfied with (x) such Memorandum of Understanding in the form submitted to them prior to the execution by the Arrangers of this Commitment Letter and (y) the operational plan discussed in the draft press release of Parent (which Parent has advised the Arrangers will be made public on the date hereof) most recently furnished by Parent to the Arrangers prior to the execution by the Arrangers of this Commitment Letter), (b) quarterly guidance for Parent and its subsidiaries for the fiscal quarter ending July 31, 2012 and (c) the contents of the letters dated June 20, 2012 and the subpoena dated July 16, 2012, each from the Division of Enforcement of the Securities and Exchange Commission to the attention of Parent, and the actions of Parent in response thereto.

Exhibit B-3

As of 4/30/2012 Navistar collateral coverage Hard Assets of Navistar and the Subsidiary Guarantors $ millions Accounts receivable $383 Inventory (ex Aftermarket Parts 1 ) $820 Net book value of Land & Buildings 2 $166 Machinery & equipment 3 $325 Tooling/Construction in progress/Short lived assets $329 Total Hard Assets $2,023 Total Hard Assets coverage 4 2.0x Stock of foreign subsidiaries 5 $263 Intellectual property Confidential Total Assets $2,286 Total collateral coverage 4 2.3x 1 Aftermarket Parts Inventory is pledged to the ABL facility 2 Excludes Principal Properties as defined in the Shy Agreement 3 Excludes Fixtures 4 Total Hard Assets over $1 billion Term Loan 5 Valued as total assets less total liabilities, (including 3 rd party debt of $0 and InterCompany debt of $0), at a 65% pledge  value EXHIBIT C CONFIDENTIAL Exhibit C-1

1 Excludes Principal Properties as defined in the Shy Agreement 2 Excludes Fixtures Collateral / Assets Description Collateral Description Comments Accounts Receivable • Includes: $383                          Inventory (ex. Aftermarket Parts) – Raw material, finished goods and used trucks, WIP, “Red Tag” and Sold Inventory – Inventory includes truck inventory in Defense, Dealcor, and Export $820 Reported at book value Net book value of  Land & Buildings¹ Includes non manufacturing facilities, such as the Lisle, IL World Headquarters, datacenters, sales and repair centers $166 Principal Properties are excluded; reported at book value Machinery & Equipment Comprised of heavy machinery such as metal bending equipment, presses, powder coat and paint apparatus, rollers and assembly line equipment $325 Reported at book value Tooling  & Patterns Dies, forms, lathes and templates for proprietary parts and component fabrication $106 Reported at book value Construction in Progress Varies from capital improvements to installations of equipment within factories $155 Other Short lived assets not carried for depreciation $68 Reported at book value Total Hard Mfg. Assets $2,023 As of 4/30/2012 Intellectual Property Medium / Bus / Severe Confidential Intellectual Property Vehicle Trademark Confidential Intellectual Property Engine Confidential Exhibit C-2 These accounts receivable are not securitized; reported at book value Know how, design, and patents for Medium, Bus, and Severe Reported at book value on percentage of completion basis Defense and Parts (Non ABL parts A/R) segments comprising 75% of A/R Truck and Engine  A/R account for the remaining  25% of A/R 2 Know how, design, and patents for engine technology International, IC Bus, Monaco and other trademark names Value ($ mm)