AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

OF

PACCAR Inc

The Corporation’s original certificate of incorporation was filed with the Secretary of State of the State of Delaware on November 19, 1971. The following Amended and Restated Certificate of Incorporation was duly proposed by the Corporation’s Board of Directors and adopted by the Corporation’s stockholders in accordance with the provisions of Sections 242 and 245 of the General Corporation Law of the State of Delaware. As a result of the foregoing, the certificate of incorporation of the Corporation is restated in its entirety as follows:

FIRST: The name of this Corporation shall be

“PACCAR Inc”.

SECOND: The Corporation’s Registered Office shall be at 251 Little Falls Drive, Wilmington, County of New Castle, Delaware 19808. The Corporation’s Registered Agent shall be The Prentice-Hall Corporation System, Inc., a Delaware corporation, the business office of which is identical with the Corporation’s Registered Office.

THIRD: The purpose of the Corporation is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of the State of Delaware.

FOURTH: The Corporation is authorized to issue 1,201,000,000 shares of stock of all classes, consisting of 1,200,000,000 shares of common stock having a par value of $1 per share and 1,000,000 shares of preferred stock having no par value. Each holder of record of shares of common stock shall be entitled to one vote for each share of stock outstanding in his name of record on the books of the Corporation. The holders of shares of preferred stock shall have no vote other than as may be provided by resolution of the Board of Directors. Other than as here expressly provided, the Board of Directors of the Corporation is expressly granted the authority to fix by resolution or resolutions, the voting power, designations, preferences and relative participating optional or other special rights and the qualifications, limitations or restrictions thereof in respect of any class or classes of stock or any shares of any class of stock of the Corporation to the full extent permitted by the General Corporation Law of the State of Delaware.

Pursuant to the foregoing authority, the Board of Directors has previously authorized the issuance of Series A Junior Participating Preferred Stock by filing a Certificate of Designations of Series A Junior Participating Preferred Stock dated January 22, 1990 with the Secretary of State of the State of Delaware on January 31, 1990, and amended same by filing an Amended Certificate of Designations of Series A Junior Participating Preferred Stock dated February 25, 1999 with the Delaware Secretary of State on March 1, 1999. The number of shares included in the Series A Junior Participating Preferred Stock, and the rights, qualifications, limitations and restrictions thereof are set forth in Appendix A hereto.

FIFTH: The original Bylaws of the Corporation may be adopted by the incorporator. Thereafter the power to make, alter or repeal Bylaws is conferred upon the Directors of the Corporation.

SIXTH: The Corporation shall have and may exercise all powers and rights, including but not limited to the power to indemnify its directors, officers, employees and agents, or any of them, in all respects as and to the full extent authorized or permitted by the General Corporation Law of the State of Delaware as the same has been heretofore or may be hereafter amended and by the provisions of this Certificate.

SEVENTH: The affirmative vote of holders of two-thirds (2/3) of the outstanding shares of stock entitled to vote shall be necessary for the following corporate actions:

EIGHTH: If any “Unfriendly Suitor” (as described below, hereafter “Suitor”) becomes the beneficial owner after the record date for the 1986 stockholders’ meeting, directly or indirectly, of twenty percent (20%) or more of the outstanding shares of stock of the Corporation, then in addition to the two-thirds (2/3) voting requirement for any transactions described in paragraphs 3, 4 or 5 of Article SEVENTH (each called “a Business Combination”), the following shall also be necessary:

The term Suitor includes any person, corporation, or affiliate and any party with which the Suitor has a direct or indirect agreement, understanding or arrangement for the purpose of acquiring, holding or voting stock of the Corporation.

The affirmative vote of two-thirds (2/3) of the outstanding shares of stock entitled to vote, other than stock held by the Suitor, shall be necessary to amend this Article EIGHTH.

NINTH:

TENTH: Any action required or permitted to be taken by the stockholders of the Corporation must be effected at a duly called annual or special meeting of stockholders and may not be effected by any consent in writing by the stockholders. Except as otherwise required by law and subject to the rights of the holders of any class or series of stock having a preference over the Common Stock as to dividends or upon liquidation, special meetings of stockholders of the Corporation may be called only by the Board of Directors pursuant to a resolution approved by a majority of the entire Board of Directors.

ELEVENTH: The liability of the Corporation’s directors to the Corporation or its stockholders shall be eliminated or limited to the fullest extent permitted by the Delaware General Corporation Law as amended from time to time. Any amendment or repeal of this Article ELEVENTH shall not adversely affect any right or protection of a director for acts or omissions prior to such amendment or repeal.

TWELFTH:

Appendix A

CERTIFICATE OF DESIGNATIONS OF

SERIES A JUNIOR PARTICIPATING PREFERRED STOCK

OF

PACCAR Inc

(Pursuant to Section 151 of the

Delaware General Corporation Law)

Section 1. Designation and Amount . The shares of such series shall be designated as “Series A Junior Participating Preferred Stock” (the “Series A Preferred Stock”) and the number of shares constituting the Series A Preferred Stock shall be 50,000. Such number of shares may be increased or decreased by resolution of the Board of Directors; provided , that no decrease shall reduce the number of shares of Series A Preferred Stock to a number less than the number of shares then outstanding plus the number of shares reserved for issuance upon the exercise of outstanding options, rights or warrants or upon the conversion of any outstanding securities issued by the Corporation convertible into Series A Preferred Stock.

Section 2. Dividends and Distributions .

(A) Subject to the rights of the holders of any shares of any series of Preferred Stock, no par value per share (the “Preferred Stock”), of the Corporation (or any similar stock) ranking prior and superior to the Series A Preferred Stock with respect to dividends, the holders of shares of Series A Preferred Stock, in preference to the holders of Common Stock, par value $1.00 per share (the “Common Stock”), of the Corporation, and of any other junior stock, shall be entitled to receive, when, as and if declared by the Board of Directors out of funds legally available for the purpose, quarterly dividends payable in cash on the first day of March, June, September and December in each year (each such date being referred to herein as a “Quarterly Dividend Payment Date”), commencing on the first Quarterly Dividend Payment Date after the first issuance of a share or fraction of a share of Series A Preferred Stock, in an amount per share (rounded to the nearest cent) equal to the greater of (a) $1 or (b) subject to the provision for adjustment hereinafter set forth, 10,000 times the aggregate per share amount of all cash dividends, and 10,000 times the aggregate per share amount (payable in kind) of all non-cash dividends or other distributions, other than a dividend payable in shares of Common Stock or a subdivision of the outstanding shares of Common Stock (by reclassification or otherwise), declared on the Common Stock since the immediately preceding Quarterly Dividend Payment Date or, with respect to the first Quarterly Dividend Payment Date, since the first issuance of any share or fraction of a share of Series A Preferred Stock. In the event the Corporation shall at any time declare or pay any dividend on the Common Stock payable in shares of Common Stock, or effect a subdivision or combination or consolidation of the outstanding shares of Common Stock (by reclassification or otherwise than by payment of a dividend in shares of Common Stock) into a greater or lesser number of shares of Common Stock, then in each such case the amount to which holders of shares of Series A Preferred Stock were entitled immediately prior to such event under clause (b) of the preceding sentence shall be adjusted by multiplying such amount by a fraction, the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

(B) The Corporation shall declare a dividend or distribution on the Series A Preferred Stock as provided in paragraph (A) of this Section immediately after it declares a dividend or distribution on the Common Stock (other than a dividend payable in shares of Common Stock); provided that, in the event no dividend or distribution shall have been declared on the Common Stock during the period between any Quarterly Dividend Payment Date and the next subsequent Quarterly Dividend Payment Date, a dividend of $1 per share on the Series A Preferred Stock shall nevertheless be payable on such subsequent Quarterly Dividend Payment Date.

(C) Dividends shall begin to accrue and be cumulative on outstanding shares of Series A Preferred Stock from the Quarterly Dividend Payment Date next preceding the date of issue of such shares, unless the date of issue of such shares is prior to the record date for the first Quarterly Dividend Payment Date, in which case dividends on such shares shall begin to accrue from the date of issue of such shares, or unless the date of issue is a Quarterly Dividend Payment Date or is a date after the record date for the determination of holders of shares of Series A Preferred Stock entitled to receive a quarterly dividend and before such Quarterly Dividend Payment Date, in either of which events such dividends shall begin to accrue and be cumulative from such Quarterly Dividend Payment Date. Accrued but unpaid dividends shall not bear interest. Dividends paid on the shares of Series A Preferred Stock in an amount less than the total amount of such dividends at the time accrued and payable on such shares shall be allocated pro rata on a share-by-share basis among all such shares at the time outstanding. The Board of Directors may fix a record date for the determination of holders of shares of Series A Preferred Stock entitled to receive payment of a dividend or distribution declared thereon, which record date shall be not more than 60 days prior to the date fixed for the payment thereof.

Section 3. Voting Rights . The holders of shares of Series A Preferred Stock shall have the following voting rights:

(A) Subject to the provision for adjustment hereinafter set forth, each share of Series A Preferred Stock shall entitle the holder thereof to 10,000 votes on all matters submitted to a vote of the stockholders of the Corporation. In the event the Corporation shall at any time declare or pay any dividend on the Common Stock payable in shares of Common Stock, or effect a subdivision or combination or consolidation of the outstanding shares of Common Stock (by reclassification or otherwise than by payment of a dividend in shares of Common Stock) into a greater or lesser number of shares of Common Stock, then in each such case the number of votes per share to which holders of shares of Series A Preferred Stock were entitled immediately prior to such event shall be adjusted by multiplying such number by a fraction, the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

(B) Except as otherwise provided herein, in any other Certificate of Designations creating a series of Preferred Stock or any similar stock, or by law, the holders of shares of Series A Preferred Stock and the holders of shares of Common Stock and any other capital stock of the Corporation having general voting rights shall vote together as one class on all matters submitted to a vote of stockholders of the Corporation.

(C) Except as set forth herein, or as otherwise provided by law, holders of Series A Preferred Stock shall have no special voting rights and their consent shall not be required (except to the extent they are entitled to vote with holders of Common Stock as set forth herein) for taking any corporate action.

Section 4. Certain Restrictions .

(A) Whenever quarterly dividends or other dividends or distributions payable on the Series A Preferred Stock as provided in Section 2 are in arrears, thereafter and until all accrued and unpaid dividends and distributions, whether or not declared, on shares of Series A Preferred Stock outstanding shall have been paid in full, the Corporation shall not:

(i) declare or pay dividends, or make any other distributions, on any shares of stock ranking junior (either as to dividends or upon liquidation, dissolution or winding up) to the Series A Preferred Stock;

(ii) declare or pay dividends, or make any other distributions, on any shares of stock ranking on a parity (either as to dividends or upon liquidation, dissolution or winding up) with the Series A Preferred Stock, except dividends paid ratably on the Series A Preferred Stock and all such parity stock on which dividends are payable or in arrears in proportion to the total amounts to which the holders of all such shares are then entitled;

(iii) redeem or purchase or otherwise acquire for consideration shares of any stock ranking junior (either as to dividends or upon liquidation, dissolution or winding up) to the Series A Preferred Stock, provided that the Corporation may at any time redeem, purchase or otherwise acquire shares of any such junior stock in exchange for shares of any stock of the Corporation ranking junior (either as to dividends or upon dissolution, liquidation or winding up) to the Series A Preferred Stock; or

(iv) redeem or purchase or otherwise acquire for consideration any shares of Series A Preferred Stock, or any shares of stock ranking on a parity with the Series A Preferred Stock, except in accordance with a purchase offer made in writing or by publication (as determined by the Board of Directors) to all holders of such shares upon such terms as the Board of Directors, after consideration of the respective annual dividend rates and other relative rights and preferences of the respective series and classes, shall determine in good faith will result in fair and equitable treatment among the respective series or classes.

(B) The Corporation shall not permit any subsidiary of the Corporation to purchase or otherwise acquire for consideration any shares of stock of the Corporation unless the Corporation could, under paragraph (A) of this Section 4, purchase or otherwise acquire such shares at such time and in such manner.

Section 5. Reacquired Shares . Any shares of Series A Preferred Stock purchased or otherwise acquired by the Corporation in any manner whatsoever shall be retired and cancelled promptly after the acquisition thereof. All such shares shall upon their cancellation become authorized but unissued shares of Preferred Stock and may be reissued as part of a new series of Preferred Stock subject to the conditions and restrictions on issuance set forth herein, in the Certificate of Incorporation, or in any other Certificate of Designations creating a series of Preferred Stock or any similar stock or as otherwise required by law.

Section 6. Liquidation, Dissolution or Winding Up . Upon any liquidation, dissolution or winding up of the Corporation, no distribution shall be made (1) to the holders of shares of stock ranking junior (either as to dividends or upon liquidation, dissolution or winding up) to the Series A Preferred Stock unless, prior thereto, the holders of shares of Series A Preferred Stock shall have received $10,000 per share, plus an amount equal to accrued and unpaid dividends and distributions thereon, whether or not declared, to the date of such payment, provided that the holders of shares of Series A Preferred Stock shall be entitled to receive an aggregate amount per share, subject to the provision for adjustment hereinafter set forth, equal to 10,000 times the aggregate amount to be distributed per share to holders of shares of Common Stock, or

(2) to the holders of shares of stock ranking on a parity (either as to dividends or upon liquidation, dissolution or winding up) with the Series A Preferred Stock, except distributions made ratably on the Series A Preferred Stock and all such parity stock in proportion to the total amounts to which the holders of all such shares are entitled upon such liquidation, dissolution or winding up. In the event the Corporation shall at any time declare or pay any dividend on the Common Stock payable in shares of Common Stock, or effect a subdivision or combination or consolidation of the outstanding shares of Common Stock (by reclassification or otherwise than by payment of a dividend in shares of Common Stock) into a greater or lesser number of shares of Common Stock, then in each such case the aggregate amount to which holders of shares of Series A Preferred Stock were entitled immediately prior to such event under the proviso in clause (1) of the preceding sentence shall be adjusted by multiplying such amount by a fraction the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

Section 7. Consolidation, Merger, etc. In case the Corporation shall enter into any consolidation, merger, combination or other transaction in which the shares of Common Stock are exchanged for or changed into other stock or securities, cash and/or any other property, then in any such case each share of Series A Preferred Stock shall at the same time be similarly exchanged or changed into an amount per share, subject to the provision for adjustment hereinafter set forth, equal to 10,000 times the aggregate amount of stock, securities, cash and/or any other property (payable in kind), as the case may be, into which or for which each share of Common Stock is changed or exchanged. In the event the Corporation shall at any time declare or pay any dividend on the Common Stock payable in shares of Common Stock, or effect a subdivision or combination or consolidation of the outstanding shares of Common Stock (by reclassification or otherwise than by payment of a dividend in shares of Common Stock) into a greater or lesser number of shares of Common Stock, then in each such case the amount set forth in the preceding sentence with respect to the exchange or change of shares of Series A Preferred Stock shall be adjusted by multiplying such amount by a fraction, the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

Section 8. No Redemption . The shares of Series A Preferred Stock shall not be redeemable.

Section 9. Rank . The Series A Preferred Stock shall rank, with respect to the payment of dividends and the distribution of assets, junior to all series of any other class of the Corporation’s Preferred Stock.

Section 10. Amendment . The Certificate of Incorporation of the Corporation shall not be amended in any manner which would materially alter or change the powers, preferences or special rights of the Series A Preferred Stock so as to affect them adversely without the affirmative vote of the holders of at least two-thirds of the outstanding shares of Series A Preferred Stock, voting together as a single class.