Exhibit 10-b


February 12, 2004

Mr. Terry E. O'Rourke


Dear Terry:

Subject:  Mutually Agreed Upon Separation

This letter confirms the substance of our conversation regarding a mutually
agreed upon separation between you and the Company. We emphasize that your
acceptance of this agreement is completely voluntary. ArvinMeritor agrees to
provide you the following:

   1.   Beginning February 1, 2004, through July 31, 2006 (the "Separation
        Period"), you will receive separation pay equal to thirty months of pay
        (at your current compensation rate of $605,000 annually), spread equally
        over the Separation Period. The Separation Period is inclusive of unused
        vacation for calendar year 2004. If you elect to retire prior to July
        31, 2006, the payments set forth in this paragraph will terminate. Your
        Separation Period will be treated as credited service under the
        ArvinMeritor Retirement Plan.

   2.   You will be eligible to receive an incentive compensation plan (ICP)
        payment for fiscal year 2004 on a prorated basis (4 months out of 12)
        for time worked during the fiscal year. Such payment will be subject to
        the applicable formula. Final award determination, if any, is subject to
        Board of Directors' approval.

   3.   You will be eligible to receive long term incentive plan (LTIP) payments
        based on your grant letters for FY2002-2004 and FY2003-2005 plan years
        as follows:

        -  FY2002-2004 LTIP will be paid in December, 2004, pending Board of
           Directors' approval based on the applicable formulas, on a pro-rated
           basis (28 months out of 36) for time worked during the performance
           cycle.

        -  FY2003-2005 LTIP will be paid in December, 2005, pending Board of
           Directors' approval, based on the applicable formulas on a prorated
           basis (16 months out of 36) for time worked during the performance
           cycle.

   4.   All outstanding stock options will continue to vest through your
        Separation Period. Stock options can be exercised up to three months
        after the last day of your Separation Period. Any option not exercised
        by October 31, 2006 will be forfeited.

Mr. Terry O'Rourke
Page 2
February 12, 2004


        If you elect to retire within thirty (30) days after the end of your
        Separation Period (July 31, 2006), your stock options that were granted
        more than 12 months prior to your retirement will continue to vest and
        can be exercised up to five years following your retirement but not
        beyond the expiration date of those options.

   5.   You received a grant of restricted stock in exchange for cancelled
        options on July 16, 2001. These restricted shares and the associated
        shares purchased with reinvested dividends, will vest on July 16, 2006.
        However, if the Company achieves performance objectives set forth in the
        Restricted Stock Agreement these restricted shares and the associated
        shares purchased with reinvested dividends will vest on January 3, 2005
        or January 3, 2006.

   6.   You also received two grants of performance contingent restricted
        shares. The first grant occurred on November 22, 2002, and the second
        grant occurred on January 2, 2004. The restrictions on these restricted
        shares will not lapse until after the corresponding LTIP performance
        cycles (FY2003-2005) (FY2004-2006), are completed and the Compensation
        and Management Development Committee of the Board of Directors
        determines the extent to which the restricted shares in the
        aforementioned grants and the associated shares purchased with
        reinvested dividends will vest as set forth in the Restricted Stock
        Agreement.

   7.   In addition, pursuant to the provisions of the Incentive Compensation
        Plan of ArvinMeritor, Inc., you received 11,445 shares of Common Stock
        (the "Deferred Share Award"). As soon as practicable after January 1,
        2005, certificates for the Deferred Shares will be delivered to you,
        pursuant to the terms and conditions of the Deferred Share Award
        Agreement.

   8.   Your present Company vehicle may be driven at Company expense through
        the end of your lease period, May 27, 2006, at which time you may
        purchase it in accordance with the Company Car Policy as though you were
        an active employee. If you elect to retire prior to May 27, 2006, you
        must immediately return your Company vehicle to the Company.

   9.   You will continue to be provided financial counseling reimbursement at
        your current annual rate through your Separation Period. If you elect to
        retire prior to the end of your Separation Period, your financial
        counseling reimbursement will terminate.

   10.  Short and long term disability coverage will cease as of January 31,
        2004.

   11.  Medical, dental, vision and flexible spending account coverage will
        remain in force through July 31, 2006. After July 31, 2006, you will be
        entitled to continue your group medical, dental, vision and flexible
        spending account coverage at your own expense for a period of up to 18
        months through COBRA. Information as to the cost of such coverage will
        be supplied following the expiration of benefits. Basic life and
        accidental death and dismemberment coverage will remain in force through
        July 31, 2006 and the life insurance coverage only may be converted to
        an individual policy within 31 days after termination of coverage by
        contacting Prudential at 800-778-3827. Payroll deductions for any
        optional life insurance and/or supplemental accidental death and
        dismemberment insurance coverage that you may have elected will continue
        through

Mr. Terry O'Rourke
Page 3
February 12, 2004


        July 31, 2006. Prudential will contact you through the mail following
        that date with regard to your ability to convert these coverages to an
        individual policy.

        Based on your age as of the end of your Separation Period you will be
        eligible to retire under the ArvinMeritor Retirement Plan. You can elect
        to retire at any time following the end of your Separation Period and
        will be able to do so by calling the ArvinMeritor Retirement Center at
        1-888-869-3772.

        Because you will not have met the minimum service requirement of ten
        years at the end of your Separation Period (July 31, 2006), you will not
        be eligible for retiree medical coverage from ArvinMeritor.

   12.  You may continue to submit your Travis Pointe Country Club expenses to
        the Company for reimbursement, during your Separation Period. Your
        membership to the Renaissance Club will be canceled immediately.

   13.  You will be eligible to continue to participate in the Company savings
        plan through the Separation Period. As a designated participant in the
        ArvinMeritor Supplemental Savings Plan you have made an irrevocable
        contribution election for 2004. If you wish to change the direction of
        your investments or your contribution level for 2005 or later, you will
        need to call T. Rowe Price at 1-800-922-9945.

   14.  You will receive Company sponsored outplacement assistance from the
        outplacement firm of your choice under the executive management program.

   15.  Your compensation checks will be mailed to your home or direct deposited
        unless you specify otherwise. Please let us know in writing if you
        change your address.

   16.  You will not disparage, portray in a negative light, or take any action
        which would be harmful to, or lead to unfavorable publicity for, the
        Company or its subsidiaries or divisions, or any of its or their current
        or former officers, directors, employees, agents, consultants,
        contractors, owners, divisions, parents or successors, whether public or
        private, including without limitation, in any and all interviews, oral
        statements, written materials, electronically displayed materials and
        materials or information displayed on Internet- or intranet-related
        sites. In the event of a breach or threatened breach of this paragraph
        16, you agree that the Company will be entitled to injunctive relief in
        a court of appropriate jurisdiction to remedy any such breach or
        threatened breach and you acknowledge that damages would be inadequate
        and insufficient.

   17.  You will deliver promptly to the Company (and not keep in your
        possession or deliver to any other person or entity) any and all
        property belonging to the Company in your possession or under your
        control, including without limitation, credit cards, software, palm
        pilots, pagers, other electronic equipment, records, data, notes,
        reports, correspondence, financial information, customer files and
        information and other documents or information (including any and all
        copies of such Company property). You may, however, retain your computer
        hardware.

   18.  You agree, on behalf of yourself, your heirs, executors, administrators
        and assigns, to release, acquit and forever discharge the Company and
        its subsidiaries and divisions

Mr. Terry O'Rourke
Page 4
February 12, 2004


        and its and their respective current and former officers, directors,
        employees, agents, owners, affiliates, successors and assigns (the
        "Company Released Parties") of and from any and all manner of actions
        and causes of action, suits, debts, damages, dues, accounts, bonds,
        covenants, contracts, agreements, judgments, charges, claims, rights and
        demands whatsoever, whether known or unknown ("Losses"), which you, your
        heirs, executors, administrators and assigns ever had, now have or may
        hereafter have, against the Company Released Parties or any of them
        arising out of or by reason of any cause, matter or thing whatsoever
        from the beginning of the world to the date hereof, including without
        limitation, any and all matters relating to your employment by the
        Company and its predecessors and the cessation thereof, any and all
        matters relating to your compensation and benefits by or from the
        Company and its predecessors and any and all matters arising under any
        federal, state or local statute, rule, regulation or principle of
        contract law or common law.

        You understand that as a result of this paragraph 18, you will not have
        the right to assert that the Company unlawfully terminated your
        employment or violated any of your rights in connection with your
        employment.

        You affirm that you have not filed, and agree not to initiate or cause
        to be initiated on your behalf, any complaint, charge, claim or
        proceeding against the Company Released Parties before any federal,
        state or local agency, court or other body relating to your employment,
        the cessation thereof or any other matters covered by the terms of this
        paragraph 18, and agree not to voluntarily participate in such a
        proceeding.

   19.  The Company and you agree that the terms and conditions of this Letter
        Agreement are confidential and that neither party will disclose the
        terms of this Letter Agreement to any third parties, other than (i)
        disclosure by you to your spouse, (ii) disclosure by the Company or you
        to its or your respective attorneys, auditors, financial advisors and
        accountants, (iii) as may be required by law (including securities laws)
        or (iv) as may be necessary to enforce this Letter Agreement. Without
        limiting the generality of the foregoing, you acknowledge that the
        Company may, to the extent required by applicable law, describe or
        incorporate the terms of this Letter Agreement in, and/or file or
        incorporate this Letter Agreement as an exhibit to, one or more filings
        with the Securities and Exchange Commission.

   20.  ArvinMeritor shall have the right to terminate this agreement at any
        time if you materially breach any of the obligations stated herein under
        this agreement.

   21.  You acknowledge that you have been advised to consult with an attorney
        prior to signing this agreement. You also acknowledge, understand and
        agree that this agreement is voluntarily entered into by you in
        consideration of the undertakings by ArvinMeritor as set forth herein
        and is consistent in all respects with the discussions by ArvinMeritor
        personnel with you relating to your separation.

   22.  You agree that for a period of eighteen months following the date of
        your departure (January 31, 2004) from the Company, you will not join or
        start a business that competes with ArvinMeritor, nor will you provide
        consultancy services, nor for the same eighteen month period will you
        solicit for employment any ArvinMeritor related employee, unless
        permission to do so is granted to you in writing by ArvinMeritor's CEO
        or his designee.

Mr. Terry O'Rourke
Page 5
February 12, 2004


        Notwithstanding the foregoing, specific companies that would be deemed
        as competing against ArvinMeritor are: Dana, Tenneco, Knorr, Federal
        Mogul, Webasto, TRW and American Axle.

        In the event there is any question as to direct or indirect competition,
        you agree to obtain approval from ArvinMeritor in writing prior to
        commencement of employment with the company which could be in
        competition. You also agree that you will not disclose, nor will you use
        any ArvinMeritor proprietary information.

   23.  This agreement is a complete and final agreement between ArvinMeritor
        and its successors and Terry O'Rourke, and supercedes all other offers,
        agreements, and negotiations except for the Invention Assignment and
        Arbitration Agreements which remain in full force.

   24.  You will have until March 29, 2004, in which to consider this agreement,
        and you may revoke this agreement within seven days of signing. This
        agreement will not become effective until the revocation period has
        expired.


Sincerely,




Larry D. Yost

cc:     V. Baker, II
        E. Whitus

                                              Accepted and Agreed by:

                                              -------------------------------
                                              Terry E. O'Rourke

                                              -------------------------------
                                              Date