THIRD SUPPLEMENTAL INDENTURE


     THIRD SUPPLEMENTAL INDENTURE, (this "Supplemental Indenture") is executed
as of the 30th day of September, 2002, among Oshkosh Logistics Corporation
(f/k/a Total Mixer Technologies Corporation), a Wisconsin corporation, Total
Mixer Technologies, L.L.C., a Wisconsin limited liability company, and Summit
Performance Systems, L.L.C., a Wisconsin limited liability company (each, a
"Guaranteeing Subsidiary" and collectively, the "Guaranteeing Subsidiaries") and
each a direct or indirect subsidiary, as the case may be, of Oshkosh Truck
Corporation, a Wisconsin corporation (the "Company"), the Company, the
Subsidiary Guarantors (as defined in the Indenture referred to herein) and U.S.
Bank, National Association, as successor in interest to Firstar Trust Company,
as trustee under the Indenture referred to below (the "Trustee"). From time to
time herein as the context requires, the Guaranteeing Subsidiaries are also
referred to as "Subsidiary Guarantors".

                               W I T N E S S E T H

     WHEREAS, the Company has heretofore executed and delivered to the Trustee
an indenture (the "Indenture"), dated as of February 26, 1998 providing for the
issuance of an aggregate principal amount of up to $150,000,000 of 8 3/4% Senior
Subordinated Notes due 2008 (the "Notes");

     WHEREAS, the Indenture provides that under certain circumstances a
Guaranteeing Subsidiary shall execute and deliver to the Trustee a supplemental
indenture pursuant to which such Guaranteeing Subsidiary shall unconditionally
guarantee all of the Company's Obligations under the Notes and the Indenture on
the terms and conditions set forth herein (the "Subsidiary Guarantee"); and

     WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

     NOW THEREFORE, in consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, the
Subsidiary Guarantors, each Guaranteeing Subsidiary and the Trustee mutually
covenant and agree for the equal and ratable benefit of the Holders of the Notes
as follows:

     1. Capitalized Terms. Capitalized terms used herein without definition
shall have the meanings assigned to them in the Indenture.

     2. Agreement to Guarantee. Each Guaranteeing Subsidiary hereby agrees as
follows:

          (a) Along with all Subsidiary Guarantors named in the Indenture, to
     jointly and severally Guarantee to each Holder of a Note authenticated and
     delivered by the Trustee and to the Trustee and its successors and assigns,
     irrespective of the validity and enforceability of the Indenture, the Notes
     or the obligations of the Company hereunder or thereunder, that:

<PAGE>

          (i)  The principal of and interest on the Notes will be promptly paid
               in full when due, whether at maturity, by acceleration,
               redemption or otherwise, and interest on the overdue principal of
               and interest on the Notes, if any, if lawful, and all other
               obligations of the Company to the Holders or the Trustee
               hereunder or thereunder will be promptly paid in full or
               performed, all in accordance with the terms hereof and thereof;
               and

          (ii) In case of any extension of time of payment or renewal of any
               Notes or any of such other obligations, that 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 any performance so guaranteed for
               whatever reason, the Subsidiary Guarantors shall be jointly and
               severally obligated to pay the same immediately.

          (b) The obligations hereunder shall be unconditional, irrespective of
     the validity, regularity or enforceability of the Notes or the Indenture,
     the absence of any action to enforce the same, any waiver or consent by any
     Holder of the Notes with respect to any provisions hereof or thereof, the
     recovery of any judgment against the Company, an action to enforce the same
     or any other circumstance which might otherwise constitute a legal or
     equitable discharge or defense of a Subsidiary Guarantor.

          (c) The following is hereby waived: 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.

          (d) This Note Guarantee shall not be discharged except by complete
     performance of the obligations contained in the Notes and the Indenture.

          (e) If any Holder or the Trustee is required by any court or otherwise
     to return to the Company, the Subsidiary Guarantors, or any Custodian,
     Trustee, liquidator or other similar official acting in relation to either
     the Company or the Subsidiary Guarantors, any amount paid by either to the
     Trustee or such Holder, this Subsidiary Guarantee, to the extent
     theretofore discharged, shall be reinstated in full force and effect.

          (f) No Subsidiary Guarantor shall be entitled to any right of
     subrogation in relation to the Holders in respect of any obligations
     guaranteed hereby until payment in full of all obligations guaranteed
     hereby.

          (g) As between the Subsidiary Guarantors, on the one hand, and the
     Holders and the Trustee, on the other hand, (x) the maturity of the
     obligations guaranteed hereby may be accelerated as provided in Article 6
     of the Indenture 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 (y) in
     the event of any

                                       2
<PAGE>

     declaration of acceleration of such obligations as provided in Article 6 of
     the Indenture, 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.

          (h) 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 the
     Guarantee.

          (i) Pursuant to Section 10.02 of the Indenture, after giving effect to
     any maximum amount and any other contingent and fixed liabilities that are
     relevant under any applicable bankruptcy or fraudulent conveyance laws, and
     after giving effect to any collections from, rights to receive contribution
     from or payments made by or on behalf of any other Subsidiary Guarantor in
     respect of the obligations of such other Subsidiary Guarantor under Article
     10 of the Indenture shall result in the obligations of such Subsidiary
     Guarantor under its Subsidiary Guarantee not constituting a fraudulent
     transfer or conveyance.

     3. Execution and Delivery. Each Guaranteeing Subsidiary agrees that the
Subsidiary Guarantees shall remain in full force and effect notwithstanding any
failure to enforce on each Note a notation of such Subsidiary Guarantee.

     4. Guaranteeing Subsidiaries May Consolidate, Etc. on Certain Terms.

          (a) No Guaranteeing Subsidiary may consolidate with or merge with or
     into (whether or not such Subsidiary Guarantor is the surviving Person)
     another corporation, Person or entity whether or not affiliated with such
     Subsidiary Guarantor unless:

               (i) subject to Section 11.05 of the Indenture, the Person formed
          by or surviving any such consolidation or merger (if other than a
          Subsidiary Guarantor or the Company) unconditionally assumes all the
          obligations of such Subsidiary Guarantor, pursuant to a supplemental
          indenture in form and substance reasonably satisfactory to the
          Trustee, under the Notes, the Indenture and the Subsidiary Guarantee
          on the terms set forth herein or therein; and

               (ii) immediately after giving effect to such transaction, no
          Default or Event of Default exists.

          (b) In case of any such consolidation, merger, sale or conveyance and
     upon the assumption by the successor corporation, by supplemental
     indenture, executed and delivered to the Trustee and satisfactory in form
     to the Trustee, of the Subsidiary Guarantee endorsed upon the Notes and the
     due and punctual performance of all of the covenants and conditions of the
     Indenture to be performed by the Subsidiary Guarantor, such successor
     corporation shall succeed to and be substituted for the Subsidiary
     Guarantor with the same effect as if it had been named herein as a
     Subsidiary Guarantor. Such successor corporation thereupon may cause to be
     singed any or all of the Subsidiary Guarantees to be endorsed upon all of
     the Notes issuable hereunder which theretofore shall not have been signed
     by the Company and delivered to the Trustee. All the Subsidiary Guarantees
     so issued shall in all respects have the same legal rank and benefit under
     the Indenture as the Subsidiary

                                       3
<PAGE>

     Guarantees theretofore and thereafter issued in accordance with the terms
     of the Indenture as though all of such Subsidiary Guarantees had been
     issued at the date of the execution hereof.

          (c) Except as set forth in Articles 4 and 5 of the Indenture, and
     notwithstanding clauses (a) and (b) above, nothing contained in the
     Indenture or in any of the Notes 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.

     5. Releases.

          (a) In the event of a sale or other disposition of all of the assets
     of any Subsidiary Guarantor, by way of merger, consolidation or otherwise,
     or a sale or other disposition of all to the capital stock of any
     Subsidiary Guarantor, then such Subsidiary Guarantor (in the event of a
     sale or other disposition, by way of merger, consolidation or otherwise, of
     all of the capital stock of such Subsidiary Guarantor) or the corporation
     acquiring the property (in the event of a sale or other disposition of all
     or substantially all of the assets of such Subsidiary Guarantor) will be
     released and relieved of any obligations under its Subsidiary Guarantee;
     provided that the Net Proceeds of such sale or other disposition are
     applied in accordance with the applicable provisions of the Indenture,
     including without limitation Section 4.10 of the Indenture. Upon delivery
     by the Company to the Trustee of an Officers' Certificate and an Opinion of
     Counsel to the effect that such sale or other disposition was made by the
     Company in accordance with the provisions of the Indenture, including
     without limitation Section 4.10 of the Indenture, the Trustee shall execute
     any documents reasonably required in order to evidence the release of any
     Subsidiary Guarantor from its obligations under its Subsidiary Guarantee.

          (b) Any Subsidiary Guarantor not released from its obligations under
     its Subsidiary Guarantee shall remain liable for the full amount of
     principal of and interest on the Notes and for the other obligations of any
     Subsidiary Guarantor under the Indenture as provided in Article 10 of the
     Indenture.

     6. No Recourse Against Others. No past, present or future director,
officer, employee, incorporator, stockholder or agent of each Guaranteeing
Subsidiary, as such, shall have any liability for any obligations of the Company
or any Guaranteeing Subsidiary under the Notes, any Subsidiary Guarantees, the
Indenture or this Supplemental Indenture or for any claim based on, in respect
of, or by reason of, such obligations or their creation. Each Holder of the
Notes by accepting a Note waives and releases all such liability. The waiver and
release are part of the consideration for the issuance of the Notes. Such waiver
may not be effective to waive liabilities under the federal securities laws and
it is the view of the Commission that such a waiver is against public policy.

                                       4
<PAGE>

     7. New York Law to Govern. THE INTERNAL LAW OF THE STATE OF NEW YORK SHALL
GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT WITHOUT GIVING
EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE
APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

     8. Counterparts. The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement.

     9. Effect of Headings. The Section headings herein are for convenience only
and shall not affect the construction hereof.

     10. The Trustee. The Trustee shall not be responsible in any manner
whatsoever for or in respect of the validity or sufficiency of this Supplemental
Indenture or for or in respect of the recitals contained herein, all of which
recitals are made solely by each Guaranteeing Subsidiary and the Company.

     IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed and attested, all as of the date first above
written.

                           OSHKOSH TRUCK CORPORATION

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           MEDTEC AMBULANCE CORPORATION

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           PIERCE WESTERN REGION
                           REFURBISHMENT CENTER, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           KEWAUNEE FABRICATIONS, L.L.C.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                                       5
<PAGE>

                           VIKING TRUCK & EQUIPMENT SALES,
                           INC., a Michigan corporation

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           VIKING TRUCK & EQUIPMENT SALES, INC., an Ohio
                           corporation

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           MCNEILUS FINANCIAL SERVICES, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           VIKING EQUIPMENT LEASING, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           MCNEILUS TRUCK & MANUFACTURING,


                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           IOWA CONTRACT FABRICATORS, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           MCINTIRE FABRICATORS, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                                       6
<PAGE>

                           KENSETT FABRICATORS, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           MCNEILUS COMPANIES, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           MCNEILUS FINANCIAL, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           PIERCE MANUFACTURING, INC.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           OSHKOSH LOGISTICS CORPORATION

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           TOTAL MIXER TECHNOLOGIES, L.L.C.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                           SUMMIT PERFORMANCE SYSTEMS, L.L.C.

                           By:   /s/ Scott L. Ney
                                 Name:  Scott L. Ney
                                 Title:  Vice President and Treasurer

                                       7
<PAGE>

                           U.S. BANK, NATIONAL
                           ASSOCIATION, as
                           Trustee

                           By:   /s/ Peter M. Brennan
                                 Name:  Peter M. Brennan
                                 Title:  Assistant Vice President

                                       8