SECOND SUPPLEMENTAL INDENTURE


          SECOND SUPPLEMENTAL INDENTURE, (this "Supplemental Indenture") dated
as of the 30th day of October, 2000, among Medtec Ambulance Corporation, an
Indiana corporation (the "Guaranteeing Subsidiary"), and a subsidiary of Oshkosh
Truck Corporation, a Wisconsin corporation (the "Company"), the Company, the
other Subsidiary Guarantors (as defined in the Indenture referred to herein) and
Firstar Bank, National Association, as successor in interest to Firstar Trust
Company, as trustee under the Indenture referred to below (the "Trustee").

                               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, 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:

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                    (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.


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               (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 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 endorse 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 10.05 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.


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               (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 signed 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
                    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


                                       -4-
<PAGE>

                    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.

          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.


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          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.

                                        MEDTEC AMBULANCE CORPORATION


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President, General
                                                 Counsel and Secretary

                                        OSHKOSH TRUCK CORPORATION


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President, General
                                                 Counsel and Secretary

                                        PIERCE WESTERN REGION
                                        REFURBISHMENT CENTER, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Secretary


                                        KEWAUNEE FABRICATIONS, L.L.C.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President, General
                                                 Counsel and Secretary

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


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary


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<PAGE>

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


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        MCNEILUS FINANCIAL SERVICES, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        VIKING EQUIPMENT LEASING, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        MCNEILUS RESCUE CORPORATION


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        MCNEILUS TRUCK & MANUFACTURING, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary


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<PAGE>

                                        IOWA CONTRACT FABRICATORS, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        MCINTIRE FABRICATORS, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        KENSETT FABRICATORS, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        MCNEILUS COMPANIES, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        MCNEILUS FINANCIAL, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary


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<PAGE>

                                        PIERCE MANUFACTURING, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: Executive Vice President
                                                 and Secretary

                                        SUMMIT PERFORMANCE SYSTEMS, INC.


                                        By: /s/ Timothy M. Dempsey
                                            ------------------------------------
                                        Name:  Timothy M. Dempsey
                                        Title: President and Secretary


                                        FIRSTAR BANK, NATIONAL ASSOCIATION,
                                        as Trustee


                                        By:
                                            ------------------------------------
                                        Name:__________________________________
                                        Title:_________________________________


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