<PAGE>
                                                                EXHIBIT 10(a)(1)


                          CORE MATERIALS CORPORATION

                           SECURED PROMISSORY NOTE
                           -----------------------


December 31, 1996                                                 $25,504,000.00


                  FOR VALUE RECEIVED, Core Materials Corporation, a Delaware
corporation (the "Company"), hereby promises to pay to the order of Navistar
International Transportation Corp., a Delaware corporation ("NAVISTAR"), the
principal amount of Twenty-Five Million Five Hundred Four Thousand and 00/100
Dollars ($25,504,000.00) (or the unpaid principal amount from time to time
outstanding hereunder) together with interest thereon calculated from the date
hereof in accordance with the provisions of this Note.

                  This Note was issued pursuant to that certain Asset Purchase
Agreement, dated as of September 12, 1996 (as amended and modified from time to
time, the "PURCHASE AGREEMENT"), between the RYMAC Mortgage Investment
Corporation (predecessor in interest to the Company) and Navistar. The Purchase
Agreement contains certain terms governing the rights of the holder of this Note
which are incorporated herein by reference. Except as defined in paragraph 10
hereof and unless otherwise indicated herein, capitalized terms used in this
Note have the same meanings set forth in the Purchase Agreement. Notwithstanding
anything to the contrary herein, it is expressly agreed that the outstanding
principal amount of this Note may, from time to time, be increased pursuant to
certain purchase price adjustments set forth in Section 1(g) of the Purchase
Agreement (the "Purchase Price Adjustments").

1. PAYMENTS OF PRINCIPAL AND INTEREST.

         (a) PRINCIPAL PAYMENT. The Company shall pay principal installments
under this Note to the Noteholder as follows:

                  (i) Within ninety (90) days after the end of each fiscal year
of the Company during the term hereof, the Company shall pay principal in an
amount equal to the amount, if any, by which the total cash and Cash Equivalents
of the Company, as shown on the Company's audited balance sheet and statement of
financial condition as of the end of such fiscal year, prepared in accordance
with GAAP, exceeds Three Million Dollars ($3,000,000.00); and

                  (ii) In the event the Company obtains, from time to time, any
Refinancing Loan, the Company shall promptly upon obtaining such loan pay
principal in an amount equal to the proceeds of such loan.

If not sooner paid, the Company shall pay the entire principal amount of this
Note then outstanding to the Noteholder in full on December 31, 2006 (the
"Maturity Date"), together with any and all accrued and unpaid interest and any
other amounts due hereunder.

         (b) INTEREST. Except as otherwise expressly provided herein, interest
shall accrue at the rate of eight percent (8.0%) per annum, (computed on the
basis of a 360-day year and the actual


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number of days elapsed in any year) on the unpaid principal amount of this Note
outstanding from time to time from and including the date hereof until the date
paid, or (if less) at the highest rate then permitted under applicable law. The
Company shall pay to the Noteholder all accrued interest on the last business
day of each June and December, beginning after the date hereof. Notwithstanding
anything to the contrary contained herein, on the date any such scheduled
interest payment becomes due the Company may elect to add such interest payment
to the outstanding principal balance of the Note to be repaid with interest in
accordance with the provisions of this Note; provided, that (i) the board of
directors of the Company by resolution declares that the payment of such
scheduled interest payment would be reasonably expected to significantly effect
the Company's and any of its Subsidiaries' ability to fund current operations
and (ii) the Noteholder shall have received written notice of such election at
least thirty (30) days before the date of such scheduled interest payment, which
notice shall be accompanied by a certified copy of the resolution of the board
of directors of the Company referred to in clause (i) above and an amendment to
this Note, in form and substance satisfactory to the Noteholder, duly executed
by the Company and dated as of the date such scheduled interest payment becomes
due, which amendment shall increase the principal amount of this Note by the
amount of such scheduled interest payment. Payments received by the Noteholder
from the Company on this Note shall be applied first to the payment of interest
which is due and payable and only thereafter to the outstanding principal
balance hereof. Unless prohibited under applicable law, any accrued interest
which is not paid on the date on which it is due and payable shall bear interest
at the same rate at which interest is then accruing on the principal amount of
this Note until such interest is paid. Any accrued interest which for any reason
has not theretofore been paid shall be paid in full on the date on which the
final principal payment on this Note is made.

2. PREPAYMENTS; SETOFF.

         (a) OPTIONAL PREPAYMENTS. The Company may, without premium or penalty,
at any time and from time to time, prepay all or any portion (in whole number
multiples of $50,000) of the outstanding principal amount of this Note, provided
that the Company has paid all interest on this Note accrued through the
immediately preceding scheduled interest payment date. In connection with any
prepayment of principal pursuant to this paragraph 2(a), the Company shall also
pay all accrued and unpaid interest on the principal amount of this Note being
prepaid.

         (b) RIGHT OF SETOFF. In addition to all other rights and remedies
available to Navistar hereunder or otherwise, Navistar shall have the right,
after the occurrence and during the continuance of any Default or Event of
Default, to setoff against and to apply to the accrued and unpaid interest and
outstanding principal balance of the Note (in each case, to the extent then due
and payable), any obligation owing by Navistar to the Company. Any such setoff
shall be applied first to the payment of interest which is due and payable and
only thereafter to the outstanding principal balance hereof.

3. COLLATERAL SECURITY. This Note is secured by a first priority lien upon and
security interest in all of the Company's assets, whether now owned or hereafter
acquired, and is entitled to the


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<PAGE>



benefits of the Security Documents. Notwithstanding the foregoing, Noteholder
agrees that it will (if requested to do so by the holder of the Senior
Obligations), upon terms reasonably acceptable to Noteholder, subordinate its
security interest and lien in the Collateral (as defined in the Security
Documents) in connection with and to the extent reasonably required to
facilitate a Refinancing Loan, and promptly upon the request of the holder of
the Senior Obligations, it will execute and deliver such documents, instruments
and agreements as are necessary to evidence such subordination.

4. COVENANTS.

         (a) AFFIRMATIVE COVENANTS; OTHER INFORMATION. The Company hereby agrees
that, so long as any amount is owing to the Noteholder hereunder, the Company
shall and (except in the case of delivery of financial information, reports and
notices) shall cause each of its Subsidiaries to:

                  (i) PERFORMANCE OF OBLIGATIONS. (A) Pay, discharge or
otherwise satisfy at or before maturity or before they become delinquent, as the
case may be, all its obligations of whatever nature, except where the amount or
validity thereof is currently being contested in good faith by appropriate
proceedings and reserves in conformity with GAAP with respect thereto have been
provided on the books of the Company or its Subsidiaries, as the case may be or
the failure to pay, discharge or otherwise satisfy such obligations would not be
reasonably expected to have a Material Adverse Effect; and (B) comply with all
material applicable laws, rules and regulations of all governmental authorities,
except to the extent that the failure to comply therewith would not be
reasonably expected to cause a Material Adverse Effect.

                  (ii) CONDUCT OF BUSINESS AND MAINTENANCE OF EXISTENCE.
Continue to engage in business of the same general type as conducted by it on
the Closing Date (after giving effect to the transactions contemplated by the
Purchase Agreement) and preserve, renew and keep in full force and effect its
corporate existence and take all reasonable action to maintain all rights,
privileges and franchises necessary or desirable in the normal conduct of its
business except as otherwise permitted pursuant to subparagraph 4(b)(iv), and
except to the extent that the failure to do so would not be reasonably expected
to have a Material Adverse Effect.

                  (iii) MAINTENANCE OF PROPERTY; INSURANCE. Keep all property
useful and necessary in its business in good working order and condition;
maintain with financially sound and reputable insurance companies insurance on
all its property in at least such amounts and against at least such risks (but
including in any event public liability) as are usually insured against in the
same general area by companies engaged in the same or a similar business; and
furnish to the Noteholder, upon written request, full information as to the
insurance carried.

                  (iv) INSPECTION OF PROPERTY; BOOKS AND RECORDS; DISCUSSIONS.
Keep proper books of records and account in which full, true and correct entries
in conformity with GAAP and applicable law shall be made of all dealings and
transactions in relation to its business and activities; and permit
representatives of the Noteholder to visit and inspect any of its properties and
examine and make abstracts from any of its books and records at any reasonable
time and upon reasonable notice and as often as may reasonably be desired and to
discuss the business,
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operations, properties and financial and other condition of the Company and
its Subsidiaries with officers and employees of the Company and its
Subsidiaries and with its independent certified public accountants;
provided that the Noteholder shall bear its own expenses if any such
inspection, examination or discussion occurs at a time when no Default or
Event of Default shall have occurred and be continuing.



                  (v)INFORMATION. Provide to Navistar:

                           (A) within five days after the same are sent, copies
of all financial statements and reports which the Company sends to its
stockholders, and within five days after the same are filed, copies of all
financial statements and reports which the Company may make to, or file with,
the Securities and Exchange Commission or any successor or analogous
governmental authority;

                           (B) promptly upon receipt thereof, any additional
reports, management letters or other detailed information concerning significant
aspects of the Company's operations or financial affairs given to the Company by
its independent accountants (and not otherwise contained in other materials
provided hereunder); and

                           (C) promptly, such additional financial and other
information as the Noteholder may from time to time reasonably request.

                  (vi) NOTICES. Reasonably promptly after obtaining knowledge of
any of the following (or within such other time period designated in clause (E)
below) give notice to the Noteholder thereof:

                           (A) the occurrence of any Default or Event of
Default;

                           (B) any (1) default or event of default under any
contractual obligation of the Company or any of its Subsidiaries or (2)
litigation, investigation or proceeding which may exist at any time between the
Company or any of its Subsidiaries and any governmental authority, which in
either case, if not cured or if adversely determined, as the case may be, could
reasonably be expected to have a Material Adverse Effect;

                           (C) any litigation or proceeding affecting the
Company or any of its Subsidiaries in which the amount involved is $250,000 or
more and not covered by insurance or in which injunctive or similar relief is
sought;

                           (D) the occurrence of or existence of any event or
condition that, in the judgment of Company, could be reasonably expected to give
rise to a claim for indemnification by the Noteholder under Section 10 of the
Purchase Agreement;

                           (E) as soon as possible and in any event within 30
days after the Company or any Commonly Controlled Entity knows or has reason to
know of (1) the occurrence or expected occurrence of any Reportable Event with
respect to any Plan, and (2) within 15 days after the Company or any Commonly
Controlled Entity knows or has reason to know of the occurrence or expected
occurrence of any of the following events: (i) a failure to make any

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required contribution to a Plan, (ii) the filing of a request for a minimum
funding waiver under Section 412 of the Code with respect to a Plan, (iii) the
creation of any Lien in favor of the PBGC or a Plan, (iv) any withdrawal from,
or the termination, Reorganization or Insolvency of, any Multiemployer Plan, (v)
the institution of proceedings or the taking of any other action by the PBGC or
the Company or any Commonly Controlled Entity or any Multiemployer Plan with
respect to the withdrawal from, or the termination, Reorganization or Insolvency
of, any Plan, (vi) the disqualification of any Plan that is intended to be
qualified under Section 401(a) of the Code, (vii) the filing of a notice of
intent to terminate a Plan or the treatment of a Plan amendment as a termination
under Section 4041 of ERISA, or (viii) any other event or condition which might
reasonably be expected to constitute grounds under Section 4042 of ERISA for the
termination of, or the appointment of a trustee to administer, any Plan or the
imposition of any liability under Title IV of ERISA;

                           (F) any Lien (other than security interests created
by the Security Agreement or Liens permitted hereunder) on any of the Collateral
(as defined in the Security Agreement) which is not permitted under subparagraph
4(b)(ii) and which, in the judgment of the Company, would be reasonably expected
to materially and adversely affect the ability of the Noteholder to exercise any
of its remedies under the Security Agreement;

                           (G) the occurrence of any event that, in the judgment
of the Company, would reasonably be expected to have a material adverse effect
on the aggregate value of the Collateral or on the security interests created by
the Security Agreement; and

                           (H) any material adverse change in the business,
operations, property or condition (financial or otherwise) of the Company and
its Subsidiaries taken as a whole.

Each notice pursuant to this paragraph shall be accompanied by a statement of a
Responsible Officer setting forth details of the occurrence referred to therein
and stating what action (if any) the Company proposes to take with respect
thereto.

                  (vii) ADDITIONAL COLLATERAL; SUBSIDIARIES.

                           (A) With respect to any assets of the type covered by
the Security Agreement acquired after the Closing Date by the Company or any of
its Subsidiaries, and, upon the occurrence and during the continuance of an
Event of Default and at the request of the Noteholder, with respect to any other
assets or property of the Company or any of its Subsidiaries, as to which the
Noteholder does not have a perfected Lien, (1) execute and deliver to the
Noteholder such amendments to the Security Agreement or such other documents as
the Noteholder reasonably requests in order to grant to the Noteholder a
security interest in such assets, (2) take all actions reasonably requested by
the Noteholder to grant to the Noteholder a perfected security interest in such
assets, including, without limitation, the filing of Uniform Commercial Code
financing statements in such jurisdictions as may be required by the Security
Agreement or by law or as may be reasonably requested by the Noteholder and (3)
if reasonably requested by the Noteholder deliver to the Noteholder legal
opinions relating to the matters described in the preceding clauses (1) and (2),
which opinions shall be in form and substance, and from counsel, reasonably
satisfactory to the Noteholder.



                                      -10-
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                           (B) With respect to any Subsidiary of the Company
created or acquired after the Closing Date by the Company, prior to or
concurrently with becoming such Subsidiary (1) have the Company amend the
Security Agreement so as to grant to the Noteholder a perfected security
interest in the Capital Stock and assets of such Subsidiary, (2) deliver to the
Noteholder or its agent the certificates representing such Capital Stock, if
any, together with undated stock powers, executed in blank, in form and
substance reasonably satisfactory to the Noteholder, in respect of such stock,
(3) cause such Subsidiary to enter into a guarantee in form and substance
reasonably satisfactory to the Noteholder guarantying the prompt payment and
performance by the Company of all of its obligations hereunder, and (4) if
requested by the Noteholder, deliver to the Noteholder legal opinions relating
to the matters described in the preceding clauses (1), (2) and (3) which
opinions shall be in form and substance, and from counsel, reasonably
satisfactory to the Noteholder.

                  (viii) OBTAIN REFINANCING LOAN. To use reasonable commercial
efforts to obtain a Refinancing Loan within six (6) months from the date hereof
in amounts and with terms reasonably satisfactory to the Company and the
Noteholder.

         (b) NEGATIVE COVENANTS. The Company hereby agrees that, so long as any
amount is owing to the Noteholder, the Company shall not, and shall not permit
any of its Subsidiaries to, directly or indirectly:

                  (i) LIMITATION ON INDEBTEDNESS. Create, incur, assume or
suffer to exist any Indebtedness, except:

                           (A) the Senior Obligations;

                           (B) Indebtedness of the Company to any Subsidiary and
of any Subsidiary to the Company or any other Subsidiary;

                           (C) Indebtedness of the Company or any of its
Subsidiaries incurred to finance the acquisition of fixed or capital assets
(whether pursuant to a loan, a Financing Lease or otherwise) after the date
hereof;

                           (D) Indebtedness assumed by the Company pursuant to
the Purchase Agreement, and any refinancings, refundings, renewals or extensions
thereof; PROVIDED, that the principal amount of any such Indebtedness shall not
be increased to more than the principal amount outstanding on the Closing Date
(after giving effect to the transactions contemplated by the Purchase
Agreement);

                           (E) Indebtedness of a corporation which becomes a
Subsidiary after the date hereof, PROVIDED that (i) such Indebtedness existed at
the time such corporation became a Subsidiary and was not created in
anticipation thereof and (ii) immediately after giving effect to the acquisition
of such corporation by the Company no Default or Event of Default shall have
occurred and be continuing;

                           (F) Indebtedness of the Company on an unsecured basis
in an aggregate principal amount not to exceed $3,000,000 at any one time
outstanding under the lines of credit


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offered by commercial banks to the Company or its Subsidiaries to finance the
working capital needs of the Company and its Subsidiaries; and

                           (G) Indebtedness of the Company in respect of this
Note, as may be amended from time to time (including without limitation any
increase in the principal amount of this Note pursuant hereto or the Purchase
Agreement).

                  (ii) LIMITATION ON LIENS. Create, incur, assume or suffer to
exist any Lien upon any of its property, assets or revenues, whether now owned
or hereafter acquired, except for:

                           (A) Liens and encumbrances of the type described in
Sections 4(c), (d) and (e) of the Purchase Agreement;

                           (B) Liens securing Indebtedness of the Company and
its Subsidiaries permitted by clause (C) of subparagraph 4(b)(i) hereof incurred
to finance the acquisition of fixed or capital assets, PROVIDED that (i) such
Liens shall be created substantially simultaneously with the acquisition of such
fixed or capital assets, (ii) such Liens do not at any time encumber any
property other than the property financed by such Indebtedness, (iii) the amount
of Indebtedness secured thereby is not increased to more than the principal
amount originally incurred and (iv) the principal amount of Indebtedness secured
by any such Lien shall at no time exceed 100% of the fair value (as determined
in good faith by the board of directors of the Company) of such property at the
time it was acquired;

                           (C) Liens on the property or assets of a corporation
which becomes a Subsidiary after the date hereof securing Indebtedness permitted
by clause (E) of subparagraph 4(b)(i) hereof, PROVIDED that (i) such Liens
existed at the time such corporation became a Subsidiary and were not created in
anticipation thereof, (ii) any such Lien is not spread to cover any property or
assets of such corporation after the time such corporation becomes a Subsidiary,
and (iii) the amount of Indebtedness secured thereby is not increased to more
than the principal amount originally incurred;

                           (D) Liens created to secure the Senior Obligations;

                           (E) Liens for taxes not yet due or which are being
contested in good faith by appropriate proceedings, provided that adequate
reserves with respect thereto are maintained on the books of the Company or its
Subsidiaries, as the case may be, in conformity with GAAP;

                           (F) carriers', warehousemen's, mechanics',
materialmen's, repairmen's or other like Liens arising in the ordinary course of
business which are not overdue for a period of more than 60 days or which are
being contested in good faith by appropriate proceedings;

                           (G) pledges or deposits in connection with workers'
compensation, unemployment insurance and other social security legislation and
deposits securing liability to insurance carriers under insurance or
self-insurance arrangements;


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                           (H) deposits to secure the performance of bids, trade
contracts (other than borrowed money), leases, statutory obligations, surety and
appeal bonds, performance bonds and other obligations of a like nature incurred
in the ordinary course of business;

                           (I) easements, rights-of-way, restrictions and other
similar encumbrances incurred in the ordinary course of business which, in the
aggregate, are not substantial in amount and which do not in any case materially
detract from the value of the property subject thereto or materially interfere
with the ordinary conduct of the business of the Company or such Subsidiary; and

                           (J) Liens created by the Security Documents.

                  (iii) LIMITATION ON GUARANTEE OBLIGATIONS. Create, incur,
assume or suffer to exist any Guarantee Obligation except:

                           (A) Guarantee Obligations assumed by the Company
pursuant to the Purchase Agreement and any refinancings, refundings, renewals or
extensions thereof, PROVIDED, that the principal amount of any such Guarantee
Obligations shall not be increased to more than the principal amount outstanding
on the Closing Date (after giving effect to the transactions contemplated by the
Purchase Agreement);

                           (B) guarantees made in the ordinary course of
business, not to exceed $250,000 in the aggregate, by the Company of obligations
of any of its Subsidiaries or by any Subsidiary of obligations of the Company,
in each case to the extent such guaranty obligations are otherwise permitted
under this Agreement;

                           (C) guarantees made in respect of the Senior
Obligations;

                           (D) guarantees by the Company or any of its
Subsidiaries of indebtedness permitted by subparagraph 4(b)(i);

                           (E) Guarantee Obligations in respect of the undrawn
portion of the face amount of letters of credit issued for the account of the
Company or any Subsidiary in an aggregate amount not to exceed $250,000 at any
one time outstanding for the Company and its Subsidiaries; and

                           (F) guarantees made in favor of the Noteholder as
contemplated by this Note.

                  (iv) LIMITATION ON FUNDAMENTAL CHANGES. Enter into any merger,
consolidation or amalgamation, or liquidate, wind up or dissolve itself (or
suffer any liquidation or dissolution), or convey, sell, lease, assign, transfer
or otherwise dispose of, all or substantially all of its property, business or
assets, or make any material change in its present method of conducting
business, except:

                           (A) any Subsidiary of the Company may be merged or
consolidated with or into the Company (PROVIDED that the Company shall be the
continuing or surviving



                                      -13-
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corporation) or with or into any one or more wholly owned Subsidiaries of the
Company (PROVIDED that the wholly owned Subsidiary or Subsidiaries shall be the
continuing or surviving corporation);

                           (B) any wholly owned Subsidiary may sell, lease,
transfer or otherwise dispose of any or all of its assets (upon voluntary
liquidation or otherwise) to the Company or any other wholly owned Subsidiary of
the Company; and

                           (C) any Person may be merged with or into the
Company, (PROVIDED that the continuing or surviving corporation assumes all of
the obligations and liabilities of the Company in respect of this Note, the
Purchase Agreement, the Ancillary Agreements, and Related Documents) with the
prior written consent of the Noteholder.

                  (v) LIMITATION ON SALE OF ASSETS. Convey, sell, lease, assign,
transfer or otherwise dispose of any of its property, business or assets
(including, without limitation, receivables and leasehold interests) or any
product line, whether now owned or hereafter acquired, or, in the case of any
Subsidiary, issue or sell any shares of such Subsidiary's Capital Stock to any
Person other than the Company or any wholly owned Subsidiary, except:

                           (A) the sale or other disposition of any property in
the ordinary course of business;

                           (B) the sale or discount without recourse of accounts
receivable arising in the ordinary course of business in connection with the
compromise or collection thereof;

                           (C) as permitted by subparagraph 4(b)(iv);

                           (D) the sale or other disposition of any property,
provided the aggregate book value of all property sold or disposed of by the
Company pursuant to this clause (D) does not exceed $1,000,000 in any fiscal
year of the Company; and

                           (E) the sale or other disposition of any assets, the
net proceeds of which are used to prepay this Note or are otherwise distributed
in accordance with the Intercreditor Agreement.

                  (vi) LIMITATION ON DIVIDENDS. Declare or pay any dividend
(other than dividends payable solely in common stock or preferred stock of the
Company and dividends payable by any Subsidiary of the Company to the Company,
or any other Subsidiary of the Company) on, or make any payment on account of,
or set apart assets for a sinking or other analogous fund for, the purchase,
redemption, defeasance, retirement or other acquisition of, any shares of any
class of Capital Stock of the Company or any warrants or options to purchase any
such Capital Stock, whether now or hereafter outstanding, or make any other
distribution in respect thereof, either directly or indirectly, whether in cash
or property or in obligations of the Company or any Subsidiary.

                  (vii) LIMITATION ON INVESTMENTS, LOANS AND ADVANCES. Make any
advance, loan, extension of credit or capital contribution to, or purchase
any stock, bonds, notes, debentures or

                                      -14-
<PAGE>




other securities of or any assets constituting a business unit of, or
make any other investment (collectively, "Investments") in, any Person, except:

                           (A) extensions of trade credit in the ordinary course
of business;

                           (B) investments in Cash Equivalents;

                           (C) investments by the Company in its Subsidiaries
and investments by such Subsidiaries in the Company and in other Subsidiaries;

                           (D) Investments in existence on the date hereof and
disclosed in the Purchase Agreement;

                           (E) additional Investments or acquisitions made after
the date hereof and approved by the board of directors of the Company; and

                           (F) loans and advances to employees of the Company or
its Subsidiaries for travel and entertainment expenses in the ordinary course of
business.

                  (viii) LIMITATION ON OPTIONAL PAYMENTS AND MODIFICATIONS OF
DEBT INSTRUMENTS. (A) Make any optional payment or prepayment on or redemption
or purchase of any Indebtedness for borrowed money other than any prepayment of
this Note or any prepayment of any revolving loans or term loans made under the
Credit Agreement; (B) amend, modify or change, or consent or agree to any
amendment, modification or change to any of the terms of any such Indebtedness
other than any such amendment, modification or change which would extend the
maturity or reduce the amount of any payment of principal thereof or which would
reduce the rate or extend the date for payment of interest thereon) or (C)
amend, modify or change, or consent or agree to any amendment, modification or
change to the Credit Agreement to increase the interest rate on the Senior
Obligations (including any default rate).

                  (ix) LIMITATION ON CHANGES IN FISCAL YEAR. Permit the fiscal
year of the Company to end on a day other than December 31.

                  (x) LIMITATION ON NEGATIVE PLEDGE CLAUSES. Enter into with any
Person any agreement, other than (A) this Note, (B) the Credit Agreement and (C)
purchase money mortgages or Financing Leases permitted by this Note (provided in
the case of this clause (C), any prohibition or limitation shall only be
effective against the assets financed thereby), which prohibits or limits the
ability of the Company or any of its Subsidiaries to create, incur, assume or
suffer to exist any Lien upon any of its property, assets or revenues, whether
now owned or hereafter acquired.

                  (xi) LIMITATION ON AMENDMENTS OF CERTIFICATES OF INCORPORATION
AND BY-LAWS. Permit any material modification, amendment or supplement to the
certificate of incorporation or by-laws of the Company or any of its
Subsidiaries.

                  (xii) LIMITATION ON CERTAIN RESTRICTIONS. Become subject to,
or permit any of its Subsidiaries to become subject to, (including, without
limitation, by way of amendment to or



                                      -15-
<PAGE>


modification of) any agreement (other than the Credit Agreement) which by its
terms would (under any circumstances) restrict (A) the right of any Subsidiary
to make loans or advances or any dividends to, transfer property to, or repay
any Indebtedness owed to, the Company or another Subsidiary or (B) the Company's
right to perform the provisions of this Note (including, without limitation,
provisions relating to the payment or prepayment of principal and interest on
this Note).

5. INTERCREDITOR AGREEMENT.

         The Noteholder hereby acknowledges and agrees that the exercise of
remedies pursuant to paragraph 6 is, and shall at all times be, subject to the
limitations on the Noteholder's remedies set forth in the Intercreditor
Agreement.

6. EVENTS OF DEFAULT.

         (a) DEFINITION. For purposes of this Note, an Event of Default shall be
deemed to have occurred if

                  (i) The Company shall fail to pay any principal when due in
accordance with the terms hereof; or the Company shall fail to pay any interest
when due in accordance with the terms hereof, or any other amount payable
hereunder, within five days after any such interest or other amount becomes due
in accordance with the terms hereof; or

                  (ii) Any representation or warranty made or deemed made by the
Company in the Purchase Agreement or any Related Document or which is contained
in any certificate, document or financial or other statement furnished by it at
any time under or in connection with this Note, the Purchase Agreement or any
Related Document shall prove to have been incorrect in any material respect on
or as of the date made or deemed made; or

                  (iii) The Company shall default in the observance or
performance of any agreement contained in subparagraph 4(a) (vii) of this Note
or contained in the Purchase Agreement or any Related Document, subject to
applicable cure periods, if any; or

                  (iv) The Company shall default in the observance or
performance of any other agreement contained in this Note subject to 30 day cure
(other than as provided in subparagraphs (i) through (iii) of this paragraph);
or

                  (v) The Company or any of its Subsidiaries shall (A) default
in any payment of principal of any Indebtedness for borrowed money in excess of
$50,000 at the final maturity thereof; or (B) default in the observance or
performance of any other agreement or condition relating to any such
Indebtedness or any Guarantee Obligation in respect of any such Indebtedness or
contained in any instrument or agreement evidencing, securing or relating
thereto, or any other event shall occur or condition exist, the effect of which
default or other event or condition is to cause such Indebtedness to become due
prior to its stated maturity or such Guarantee Obligation to become payable
(whether by the terms of any document evidencing such Indebtedness or Guarantee
Obligation, upon the election of any holder of Indebtedness or beneficiary of
any Guarantee Obligation or otherwise); or


                                      -16-
<PAGE>


                  (vi) (A) The Company or any of its Subsidiaries shall commence
any case, proceeding or other action (1) under any existing or future law of any
jurisdiction, domestic or foreign, relating to bankruptcy, insolvency,
reorganization or relief of debtors, seeking to have an order for relief entered
with respect to it, or seeking to adjudicate it a bankrupt or insolvent, or
seeking reorganization, arrangement, adjustment, winding-up, liquidation,
dissolution, composition or other relief with respect to it or its debts, or (2)
seeking appointment of a receiver, trustee, custodian, conservator or other
similar official for it or for all or any substantial part of its assets, or the
Company or any of its Subsidiaries shall make a general assignment for the
benefit of its creditors; or (B) there shall be commenced against the Company or
any of its Subsidiaries any case, proceeding or other action of a nature
referred to in clause (A) above which (1) results in the entry of an order for
relief or any such adjudication or appointment or (2) remains undismissed,
undischarged or unbonded for a period of 60 days; or (C) there shall be
commenced against the Company or any of its Subsidiaries any case, proceeding or
other action seeking issuance of a warrant of attachment, execution, distraint
or similar process against all or any substantial part of its assets which
results in the entry of an order for any such relief which shall not have been
vacated, discharged, or stayed or bonded pending appeal within 60 days from the
entry thereof; or (D) the Company or any of its Subsidiaries shall take any
action in furtherance of, or indicating its consent to, approval of, or
acquiescence in, any of the acts set forth in clause (A), (B), or (C) above; or
(E) the Company or any of its Subsidiaries shall generally not, or shall be
unable to, or shall admit in writing its inability to, pay its debts as they
become due; or

                  (vii) (A) Any Person shall engage in any "prohibited
transaction" (as defined in Section 406 of ERISA or Section 4975 of the Code)
involving any Plan, (B) any "accumulated funding deficiency" (as defined in
Section 302 of ERISA), whether or not waived, shall exist with respect to any
Plan or any Lien in favor of the PBGC or a Plan shall arise on the assets of the
Company or any Commonly Controlled Entity, (C) a Reportable Event shall occur
with respect to, or proceedings shall commence to have a trustee appointed, or a
trustee shall be appointed, to administer or to terminate, any Plan that is a
Single-Employer Plan, (D) any Plan that is a Single-Employer Plan shall
terminate for purposes of Title IV of ERISA, (E) the Company or any Commonly
Controlled Entity shall, or in the reasonable opinion of Noteholder is likely
to, incur any liability in connection with a withdrawal from, or the Insolvency
or Reorganization of, a Multiemployer Plan or (F) any other event or condition
shall occur or exist with respect to a Plan; and in each case in clauses (A)
through (F) above, such event or condition, together with all other such events
or conditions, if any, could reasonably be expected to have a Material Adverse
Effect; or

                  (viii) One or more judgments or decrees shall be entered
against the Company or any of its Subsidiaries involving in the aggregate a
liability (not fully covered by insurance) of $1,000,000 or more, and all such
judgments or decrees shall not have been vacated, discharged, stayed or bonded
pending appeal within 60 days from the entry thereof; or

                  (ix) (A) Any of the Security Documents shall cease, for any
reason, to be in full force and effect, or the Company or any Subsidiary which
is a party to any of the Security Documents shall so assert or (B) the Lien
created by any of the Security Documents shall cease to be enforceable and of
the same effect and priority purported to be created thereby, except to the
extent, if any, otherwise provided in the Intercreditor Agreement.



                                      -17-
<PAGE>

         (b)      CONSEQUENCES OF EVENTS OF DEFAULT.

                  (i) If any Event of Default has occurred, the interest rate on
this Note shall increase immediately by an increment of 1 percentage point(s) to
the extent permitted by law. Any increase of the interest rate resulting from
the operation of this subparagraph shall terminate as of the close of business
on the date on which no Events of Default exist.

                  (ii) If an Event of Default of the type described in
subparagraph 6(a) (vi) has occurred with respect to the Company, the aggregate
principal amount of this Note (together with all accrued interest thereon and
all other amounts due and payable with respect thereto) shall become immediately
due and payable without any action on the part of the Noteholder, and the
Company shall immediately pay to the Noteholder all amounts due and payable with
respect to this Note.

                  (iii) If any Event of Default has occurred (other than under
subparagraph 6(a) (vi)), the Noteholder may declare all or any portion of the
outstanding principal amount of this Note (together with all accrued interest
thereon and all other amounts due and payable with respect thereto) to be
immediately due and payable and may demand immediate payment of all or any
portion of the outstanding principal amount of this Note (together with all such
other amounts then due and payable).

                  (iv) The Noteholder shall also have any other rights which
such holder may have been afforded under any contract or agreement (including,
without limitation, the Security Documents) at any time and any other rights
which such holder may have pursuant to applicable law.

7. WAIVER OF CERTAIN RIGHTS. The Company hereby waives diligence, presentment,
protest and demand and notice of protest and demand, dishonor and nonpayment of
this Note, and expressly agrees that this Note, or any payment hereunder, may be
extended from time to time and that the holder hereof may accept security for
this Note or release security for this Note, all without in any way affecting
the liability of the Company hereunder.

8. ASSIGNMENT. The rights and obligations of the Company and the Noteholder
shall be binding upon and benefit the permitted successors, assigns and
transferee of the parties; provided that in no event shall the Company assign
its rights hereunder without the prior written consent of the Noteholder. The
Noteholder shall provide the Company with notice of any assignment or transfer
of Noteholder's rights hereunder.

9. AMENDMENT AND WAIVER. Except as otherwise expressly provided herein, the
provisions of this Note may be amended and the Company may take any action
herein prohibited, or omit to perform any act herein required to be performed by
it, only if the Company has obtained the written consent of the Noteholder.

10. DEFINITIONS. For purposes of this Note, the following capitalized terms have
the following meaning:


                                      -18-
<PAGE>

         "CAPITAL STOCK" shall mean any and all shares, interests,
participations or other equivalents (however designated) of capital stock of a
corporation, any and all equivalent ownership interests in a Person (other than
a corporation) and any and all warrants or options to purchase any of the
foregoing.

         "CASH EQUIVALENTS" shall mean (a) securities with maturities of one
year or less from the date of acquisition issued or fully guaranteed or insured
by the United States Government or any agency thereof, (b) certificates of
deposit and eurodollar time deposits with maturities of one year or less from
the date of acquisition and overnight bank deposits of any commercial bank
having capital and surplus in excess of $250,000,000, or party to the Credit
Agreement (c) repurchase obligations of any commercial bank satisfying the
requirements of clause (b) of this definition, having a term of not more than 30
days with respect to securities issued or fully guaranteed or insured by the
United States Government, (d) commercial paper of a domestic issuer rated at
least A-2 by Standard and Poor's Ratings Group ("S&P") or P-2 by Moody's
Investors Service, Inc. ("Moody's"), (e) securities with maturities of one year
or less from the date of acquisition issued or fully guaranteed by any state,
commonwealth or territory of the United States or by any political subdivision
or taxing authority of any such state, commonwealth or territory or by any
foreign government, the securities of which state, commonwealth, territory,
political subdivision, taxing authority or foreign government (as the case may
be) are rated at least A by S&P or A by Moody's, (f) securities with maturities
of one year or less from the date of acquisition backed by standby letters of
credit issued by any commercial bank satisfying the requirements of clause (b)
of this definition or (g) shares of money market mutual or similar funds which
invest exclusively in assets satisfying the requirements of clauses (b) through
(f) of this definition;

         "COMMONLY CONTROLLED ENTITY" shall mean an entity, whether or not
incorporated, which is under common control with the Company within the meaning
of Section 4001 of ERISA or is part of a group which includes the Company and
which is treated as a single employer under Section 414 of the Code.

         "CONSOLIDATED LEASE EXPENSE" shall mean for any period, the aggregate
amount of fixed and contingent rentals payable by the Company and its
Subsidiaries for such period with respect to leases of real and personal
property, determined in accordance with GAAP on a consolidated basis.

         "DEFAULT" shall mean any of the events specified in paragraph 6,
whether or not any requirement for the giving of notice, the lapse of time, or
both, or any other condition, has been satisfied.

         "EMPLOYEE BENEFIT PLAN" shall have the meaning set forth in Section
3(3) of ERISA.

         "ERISA" shall mean the Employee Retirement Income Security Act of 1974,
as amended from time to time.

         "EVENT OF DEFAULT" shall mean each of the events described in paragraph
6; PROVIDED, HOWEVER, that any requirement for the giving of notice, the lapse
of time, or both, or any other condition, has been satisfied.


                                      -19-
<PAGE>


         "FINANCING LEASE" shall mean any lease of property, real or personal,
the obligations of the lessee in respect of which are required in accordance
with GAAP to be capitalized on a balance sheet of the lessee.

         "GUARANTEE OBLIGATION" shall mean as to any Person (the "GUARANTEEING
PERSON"), any obligation of (a) the guaranteeing person or (b) another Person
(including, without limitation, any bank under any letter of credit) to induce
the creation of which the guaranteeing person has issued a reimbursement,
counterindemnity or similar obligation, in either case guaranteeing or in effect
guaranteeing any Indebtedness, leases, dividends or other obligations (the
"PRIMARY OBLIGATIONS") of any other third Person (the "PRIMARY OBLIGOR") in any
manner, whether directly or indirectly, including, without limitation, any
obligation of the guaranteeing person, whether or not contingent, (i) to
purchase any such primary obligation or any property constituting direct or
indirect security therefor, (ii) to advance or supply funds (1) for the purchase
or payment of any such primary obligation or (2) to maintain working capital or
equity capital of the primary obligor or otherwise to maintain the net worth or
solvency of the primary obligor, (iii) to purchase property, securities or
services primarily for the purpose of assuring the owner of any such primary
obligation of the ability of the primary obligor to make payment of such primary
obligation or (iv) otherwise to assure or hold harmless the owner of any such
primary obligation against loss in respect thereof; PROVIDED, HOWEVER, that the
term Guarantee Obligation shall not include endorsements of instruments for
deposit or collection in the ordinary course of business. The amount of any
Guarantee Obligation of any guaranteeing person shall be deemed to be the lower
of (a) an amount equal to the stated or determinable amount of the primary
obligation in respect of which such Guarantee Obligation is made and (b) the
maximum amount for which such guaranteeing person may be liable pursuant to the
terms of the instrument embodying such Guarantee Obligation, unless such primary
obligation and the maximum amount for which such guaranteeing person may be
liable are not stated or determinable, in which case the amount of such
Guarantee Obligation shall be such guaranteeing person's maximum reasonably
anticipated liability in respect thereof as determined by the Company in good
faith.

         "INDEBTEDNESS" shall mean of any Person at any date, (a) all
indebtedness of such Person for borrowed money or for the deferred purchase
price of property or services (other than current trade liabilities incurred in
the ordinary course of business and payable in accordance with customary
practices), (b) any other indebtedness of such Person which is evidenced by a
note, bond, debenture or similar instrument, (c) all obligations of such Person
under Financing Leases, (d) all obligations of such Person in respect of
acceptances issued or created for the account of such Person, (e) all
obligations in respect of deferred compensation and (f) all liabilities secured
by any Lien on any property owned by such Person even though such Person has not
assumed or otherwise become liable for the payment thereof.

         "INSOLVENCY" shall mean with respect to any Multiemployer Plan, the
condition that such Plan is insolvent within the meaning of Section 4245 of
ERISA.

         "INTERCREDITOR AGREEMENT" shall mean the intercreditor agreement
entered into between the holders of Senior Obligations and Navistar, as amended
or otherwise modified from time to time.


                                      -20-
<PAGE>

         "LIEN" shall mean any mortgage, pledge, hypothecation, assignment,
deposit arrangement, encumbrance, lien (statutory or other), charge or other
security interest or any preference, priority or other security agreement or
preferential arrangement of any kind or nature whatsoever (including, without
limitation, any conditional sale or other title retention agreement and any
Financing Lease having substantially the same economic effect as any of the
foregoing).

         "MATERIAL ADVERSE EFFECT" shall mean a material adverse effect on (a)
the business, operations, property or condition (financial or otherwise) of the
Company and its Subsidiaries taken as a whole or (b) the validity or
enforceability of this Note or any of the other Related Documents (other than
the Intercreditor Agreement) or the rights or remedies of Noteholder hereunder
or thereunder.

         "MULTIEMPLOYER PLAN" shall mean a Plan which is a multiemployer plan as
defined in Section 400l(a)(3) of ERISA.

         "NOTEHOLDER" shall mean Navistar and its permitted successors,
transferees and assigns.

         "PBGC" shall mean the Pension Benefit Guaranty Corporation established
pursuant to Subtitle A of Title IV of ERISA.

         "PERSON" shall mean an individual, partnership, corporation, business
trust, joint stock company, trust, unincorporated association, joint venture,
Governmental Authority or other entity of whatever nature.

         "PLAN" shall mean any Employee Benefit Plan in respect of which the
Company or a Commonly Controlled Entity is (or, if such plan were terminated at
such time, would under Section 4069 of ERISA be deemed to be) an "employer" as
defined in Section 3(5) of ERISA.

         "REFINANCING LOAN" shall mean any loan, extension of credit or other
financial accommodation (other than a revolving line of credit for working
capital purposes or loans for project finance use) made as of or after the
Closing to the Company by a Person other than the Noteholder, to refinance and
pay indefeasibly in full or in part the outstanding principal amount now or at
any time or times hereafter owing by the Company to Noteholder under this Note,
and which is secured by Company's equipment or other assets in which Noteholder
holds security interests on the date hereof, provided that (i) the proceeds of
such loan are disbursed directly to Noteholder pursuant to written authorization
given by Company to the Person making the loan; and (ii) to the extent such
Person intends to take a security interest in any of Company's equipment or
other assets, such person has entered into an intercreditor agreement with the
Noteholder in form and substance acceptable to Noteholder.

         "RELATED DOCUMENTS" shall mean this Note, the Security Documents and
the Intercreditor Agreement.

         "REORGANIZATION" shall mean with respect to any Multiemployer Plan, the
condition that such plan is in reorganization within the meaning of Section 4241
of ERISA.



                                      -21-
<PAGE>

         "REPORTABLE EVENT" shall mean any of the events set forth in Section
4043(b) of ERISA, other than those events as to which the thirty day notice
period is waived by regulation.

         "RESPONSIBLE OFFICER" shall mean the chief executive officer and the
president of the Company or, with respect to financial matters, the chief
financial officer of the Company.

         "SENIOR OBLIGATIONS" shall mean all obligations and liabilities of the
Company in respect of the loan agreement entered into by the Company in
connection with the Refinancing Loan (the "CREDIT AGREEMENT") and all loan and
security documents executed and delivered in connection therewith, and any
refinancing, refunding, renewals or extensions thereof (PROVIDED, that the
principal amount of such Indebtedness shall not be increased to more than the
principal amount outstanding as of the date of such loan agreement), including,
without limitation, any interest accruing subsequent to the commencement of any
bankruptcy, insolvency or similar proceedings with respect to the Company,
whether or not such interest constitutes an allowed claim in such proceeding.

         "SECURITY AGREEMENT" shall mean (i) the Open-End Mortgage Deed and
Security Agreement dated as of December 31, 1996 given by the Company in favor
of the Navistar and filed for record with the Franklin County, Ohio, Recorder,
and (ii) the Security Agreement dated as of December 31, 1996 given by the
Company in favor of Navistar.

         "SECURITY DOCUMENTS" shall mean the Security Agreement, and the
subsidiary guarantees contemplated hereby.

         "SINGLE-EMPLOYER PLAN" shall have the meaning set forth in Section
4001(a)(15) of ERISA.

         "SUBSIDIARY" shall mean as to any Person, a corporation, partnership or
other entity of which shares of stock or other ownership interests having
ordinary voting power (other than stock or such other ownership interests having
such power only by reason of the happening of a contingency) to elect a majority
of the board of directors or other managers of such corporation, partnership or
other entity are at the time owned, or the management of which is otherwise
controlled, directly or indirectly through one or more intermediaries, or both,
by such Person. Unless otherwise qualified, all references to a "Subsidiary" or
to "Subsidiaries" in this Note shall refer to a Subsidiary or Subsidiaries of
the Company.

11. CANCELLATION. After all principal, accrued interest and all other amounts
hereunder at any time owed on this Note, including all Purchase Price
Adjustments, have been paid in full, this Note shall be surrendered to the
Company for cancellation, and the Noteholder shall take such action as the
Company may reasonably request to evidence such discharge and the release of the
Liens created by the Security Documents. Notwithstanding anything herein to the
contrary, it is expressly agreed that the outstanding principal balance under
this Note may be reduced to a zero balance without such repayment operating to
cancel this Note or extinguish or release the Liens, security title and security
interest created by the Security Documents. This Note and the Security Documents
shall remain in full force and effect as to any subsequent Purchase Price
Adjustments made after the zero balance without loss or priority until all
Indebtedness of the Company to the


                                      -22-
<PAGE>


Noteholder arising under or in connection with this Note, the Purchase
Agreement, or any other instrument or document now or at any time evidencing,
securing or guaranteeing the same is paid in full and satisfied. The Company
waives the operation of any applicable statute, law or regulation having a
contrary effect.

12. PAYMENT OF EXPENSES AND TAXES. The Company hereby agrees (a) to pay or
reimburse the Noteholder for all its costs and expenses incurred in connection
with the enforcement or preservation of any rights under this Note and the other
Related Documents after the occurrence of any Event of Default, including,
without limitation, the reasonable fees and disbursements of counsel to the
Noteholder, (b) to pay, indemnify, and hold the Noteholder harmless from, any
and all recording and filing fees and any and all liabilities with respect to,
or resulting from any delay in paying, stamp, excise and other similar taxes, if
any, which may be payable or determined to be payable in connection with the
execution and delivery of, or consummation or administration of any of the
transactions contemplated by, or any amendment, supplement or modification of,
or any waiver or consent under or in respect of, this Note and the other Related
Documents and (c) to pay, indemnify, and hold the Noteholder harmless from and
against any and all other liabilities, obligations, losses, damages, penalties,
actions, judgments, suits, costs, expenses or disbursements of any kind or
nature whatsoever with respect to the execution, delivery, enforcement,
performance and administration of this Note and the other Related Documents,
including, without limitation, any of the foregoing relating to the violation
of, noncompliance with or liability under, any Environmental Law applicable to
the operations of the Company, any of its Subsidiaries or any of their
properties (all the foregoing in this clause (c), collectively, the "indemnified
liabilities"), PROVIDED that the Company shall have no obligation hereunder to
the Noteholder with respect to indemnified liabilities arising from (i) the
gross negligence or willful misconduct of the Noteholder, (ii) legal proceedings
commenced against the Noteholder by any security holder or creditor thereof
arising out of and based upon rights afforded any such security holder or
creditor solely in its capacity as such or (iii) any matter relating to the
Intercreditor Agreement. The agreements in this paragraph shall survive
repayment of this Note and all other amounts payable hereunder.

13. PAYMENTS. All payments to be made to the Noteholder shall be made in the
lawful money of the United States of America in immediately available funds and,
except as otherwise expressly provided herein or as may be required by law,
without any setoff, counterclaim, withholding or deduction whatsoever.

14. PLACE OF PAYMENT. Payments of principal and interest shall be delivered to
Navistar by wire transfer of immediately available funds to the following
account:

                                    Bank of America, Illinois
                                    231 South LaSalle Street
                                    Chicago, Illinois  60697
                                    ABA Routing Number:  071000039
                                    For the account of
                                    Navistar International Transportation Corp.

                                      -23-
<PAGE>

or to such other Noteholder at such other address or to the attention of such
other person or to such other account as specified by prior written notice to
the Company.

15. SEVERABILITY. Whenever possible, each provision of this Note shall be
interpreted in such manner as to be effective and valid under applicable law,
but if any provision of this Note is held to be prohibited by or invalid under
applicable law, such provision shall be ineffective only to the extent of such
prohibition or invalidity, without invalidating the remainder of this Note.

16. DESCRIPTIVE HEADINGS; INTERPRETATION. The descriptive headings of this Note
are inserted for convenience only and do not constitute a substantive part of
this Note. The use of the word "including" in this Note shall be by way of
example rather than by limitation.

17. GOVERNING LAW. ALL ISSUES AND QUESTIONS CONCERNING THE CONSTRUCTION,
VALIDITY, ENFORCEMENT AND INTERPRETATION OF THIS NOTE SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF ILLINOIS, WITHOUT GIVING
EFFECT TO ANY CHOICE OF LAW OR CONFLICT OF LAW RULES OR PROVISIONS (WHETHER OF
THE STATE OF ILLINOIS OR ANY OTHER JURISDICTION) THAT WOULD CAUSE THE
APPLICATION OF THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF ILLINOIS.

18. WAIVERS. TO THE EXTENT PERMITTED BY LAW, THE COMPANY HEREBY WAIVES PERSONAL
SERVICE OF ANY AND ALL PROCESS UPON IT AND CONSENTS THAT ALL SUCH SERVICE OF
PROCESS BE MADE BY CERTIFIED REGISTERED MAIL DIRECTED TO IT AT ITS ADDRESS SET
FORTH IN PARAGRAPH 19 HEREOF. IN ADDITION, THE COMPANY HEREBY WAIVES TRIAL BY
JURY, ANY OBJECTIONS BASED ON FORUM NON CONVENIENS AND ANY OBJECTIONS TO VENUE
OF ANY ACTION ARISING OUT OF, CONNECTED WITH, RELATED TO OR INCIDENTAL TO THE
TRANSACTIONS CONTEMPLATED BY OR THE RELATIONSHIPS ESTABLISHED IN CONNECTION WITH
THIS NOTE.

19. NOTICES. All notices, requests, demands, waivers and other communication
required or permitted to be given under this Note shall be in writing and shall
be deemed to have been duly given if (i) delivered personally, (ii) mailed by
first-class, registered or certified mail, return receipt requested, postage
prepaid, or (iii) sent by next-day or overnight mail or delivery or (iv) sent by
telecopy (with verbal confirmation of receipt) or telegram.

         IF TO NAVISTAR:
         ---------------

         455 North City Front Plaza Drive
         Chicago, IL  60611
         Attn:    Treasurer
         Fax Number: (312) 836-2573

         WITH A COPY, WHICH WILL
         NOT CONSTITUTE NOTICE TO
         NAVISTAR, TO:
         455 North City Front Plaza Drive
         Chicago, IL  60611




                                      -24-
<PAGE>


         Attn:    General Counsel
         Fax Number: (312) 836-3982

         and:

         Kirkland & Ellis
         200 East Randolph Drive
         Chicago, IL  60601
         Attn:    Michael Kerr
         Fax Number: (312) 861-2200
         Confirm Number: (312) 861-2356

         IF TO THE COMPANY:

         Core Materials Corporation
         800 Manor Park Drive
         Columbus, Ohio 43228
         Attn:  President
         Fax Number:  (614) 870-5051

         WITH A COPY, WHICH WILL
         NOT CONSTITUTE NOTICE TO
         THE COMPANY, TO:

         Brown & Wood LLP
         One World Trade Center
         New York, New York, 10048
         Attn:  Edward J. Fine, Esquire
         Fax Number:  (212) 839-5599

or, in each case, to such other Noteholder at such other address as may be
specified in writing to the other Parties.

All such notices, requests, demands, waivers and other communications shall be
deemed to have been received (i) if by personal delivery on the date after such
delivery, (ii) if by certified or registered mail, on the seventh business day
after the mailing thereof, (iii) if by next-day or overnight mail or delivery,
on the day delivered, or (iv) if by telecopy or telegram, on the next day
following the day on which such telecopy or telegram was sent, provided that a
copy is also sent by certified or registered mail.

20. BUSINESS DAYS. If any payment is due, or any time period for giving notice
or taking action expires, on a day which is a Saturday, Sunday or legal holiday
in the State of Illinois, the payment shall be due and payable on, and the time
period shall automatically be extended to, the next business day immediately
following such Saturday, Sunday or legal holiday, and interest shall continue to
accrue at the required rate hereunder until any such payment is made.


                                      -25-
<PAGE>

21. USURY LAWS. It is the intention of the Company and the Noteholder to conform
strictly to all applicable usury laws now or hereafter in force, and any
interest payable under this Note shall be subject to reduction to the amount not
in excess of the maximum legal amount allowed under the applicable usury laws as
now or hereafter construed by the courts having jurisdiction over such matters.
If the maturity of this Note is accelerated by reason of an election by the
holder hereof resulting from an Event of Default, voluntary prepayment by the
Company or otherwise, then earned interest may never include more than the
maximum amount permitted by law, computed from the date hereof until payment,
and any interest in excess of the maximum amount permitted by law shall be
canceled automatically and, if theretofore paid, shall at the option of the
holder hereof either be rebated to the Company or credited on the principal
amount of this Note, or if this Note has been paid, then the excess shall be
rebated to the Company. The aggregate of all interest (whether designated as
interest, service charges, points or otherwise) contracted for, chargeable, or
receivable under this Note shall under no circumstances exceed the maximum legal
rate upon the unpaid principal balance of this Note remaining unpaid from time
to time. If such interest does exceed the maximum legal rate, it shall be deemed
a mistake and such excess shall be canceled automatically and, if theretofore
paid, rebated to the Company or credited on the principal amount of this Note,
or if this Note has been repaid, then such excess shall be rebated to the
Company.

         IN WITNESS WHEREOF, the Company has executed and delivered this Note as
of December 31, 1996.

                           CORE MATERIALS CORPORATION

                           By: /s/ Richard R. Conte
                               ----------------------------

                           Its: President
                                ----------------------------



                                      -26-