**UNITED      STATES**

**SECURITIES      AND EXCHANGE COMMISSION**

**Washington,      D.C. 20549**

**FORM      8-K**

**CURRENT      REPORT**

**Pursuant      to Section 13 or 15(d) of the Securities Exchange Act of      1934**

**Date      of Report (Date of earliest event reported): August 9,      2006**

**NAVISTAR      INTERNATIONAL CORPORATION**

| Delaware                                                                                    |   | 1-9618                               |   | 36-3359573                                                        |
|---------------------------------------------------------------------------------------------|--------|--------------------------------------|--------|-------------------------------------------------------------------|
|                                                                                             |   |                                      |   |                                                                   |
| (State                or other jurisdiction ofincorporation                or organization) |   | (Commission                File No.) |   | (I.R.S.                EmployerIdentification                No.) |

| 4201                Winfield Road, P.O. Box 1488, Warrenville, Illinois |   | 60555                     |
|-------------------------------------------------------------------------|--------|---------------------------|
|                                                                         |   |                           |
| (Address                of principal executive offices)                 |   | (Zip                Code) |

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**ITEM      **
**3.03**
**MATERIAL      MODIFICATION TO RIGHTS OF SECURITY HOLDERS**

**ITEM      9.01 **
**FINANCIAL      STATEMENTS AND EXHIBITS**

|   | (d)  | Exhibit                    |   |                                                                                                                                                                                                                                                                                                                                                                     |   |   |
|--------|-----------|----------------------------|--------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|--------|
|   |      |                       |   |                                                                                                                                                                                                                                                                                                                                                                     |   |   |
|   |      | Exhibit                No. |   | Description                                                                                                                                                                                                                                                                                                                                                              |   | Page   |
|   |      |                            |   |                                                                                                                                                                                                                                                                                                                                                                          |   |        |
|   |      |                       |   |                                                                                                                                                                                                                                                                                                                                                                     |   |   |
|   |      | 4.50                       |   | First                Supplement, dated as of August 9, 2006, to Indenture by and among                Navistar                International Corporation, International Truck and Engine Corporation                and                BNY Midwest Trust Company, as Trustee, for 2.50% Senior Convertible                Notes                due 2007 for $190,000,000. |   | E-1    |
|   |      |                       |   |                                                                                                                                                                                                                                                                                                                                                                     |   |   |

**Forward-looking      information**

*Information      provided and statements contained in the presentation that are not purely      historical are forward -looking statements within the meaning of Section 27A      of      the Securities Act and Section 21E of the Exchange Act, and the Private      Securities Litigation Reform Act of 1995. Such forward-looking statements only      speak as of the date of the presentation and the company assumes no obligation      to update the information included in the presentation. Such forward-looking      statements include information concerning our possible or assumed future results      of operations, including descriptions of our business strategy. These statements      often include words such as “believe,” “expect,” “anticipate,” “intend,” “plan,”“estimate” or similar expressions. These statements are not guarantees of      performance or results and they involve risks, uncertainties and assumptions      ,      including the risk of continued delay in the completion of our financial      statements and the consequences thereof, the availability of funds, either      through cash on hand or the company’s other liquidity sources, to repay any      amounts due should any of the company’s debt become accelerated, and decisions      by suppliers and other vendors to restrict or eliminate customary trade and      other credit terms for the company’s future orders and other services, which      would require the company to pay cash and which could have a material adverse      effect on the company’s liquidity position and financial condition. Although we      believe that these forward-looking statements are based on reasonable      assumptions, there are many factors that could affect our actual financial      results or results of operations and could cause actual results to differ      materially from those in the forward-looking statements. For a further      description of these factors, see Exhibit 99.1 to our Form 8-K filed      on April 12, 2006.*

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| Date:                August 9, 2006 | /s/Robert                C. Lannert                                                                     |
|-------------------------------------|---------------------------------------------------------------------------------------------------------|
|                                |                                                                                                         |
|                                | Robert                C. LannertVice                Chairman and Chief Financial                Officer |