EXHIBIT 10.4

                       AMENDMENT TO STOCKHOLDERS AGREEMENT


         This Amendment to Stockholders Agreement (the "Amendment"), dated as of
July ___, 1996, between MK Rail Corporation, a Delaware corporation ("MK Rail"),
and Morrison Knudsen Corporation, an Ohio corporation ("MKO").

         WHEREAS,  in connection  with the  reorganization  of Morrison  Knudsen
Corporation,  a Delaware  corporation  ("MK"), in a case filed under Title 11 of
the United States  Bankruptcy Code, as amended (the "Bankruptcy  Code"), MK Rail
and MKO executed and delivered a Stockholders  Agreement (the "Agreement") dated
as June 20, 1996; and

         WHEREAS,  the  Agreement  contains  certain  agreements  regarding  the
registration and voting of restricted  shares of common stock of MK Rail held by
MKO which stock it was contemplated would be distributed to certain creditors of
MK and MKO; and

         WHEREAS,  as a result of negotiations  between MK and equity holders of
MK, it is contemplated that MK's plan of reorganization  will be amended so that
it  provides  for rights or options to be granted to equity  holders of MK which
will permit them,  subject to satisfaction of certain  conditions,  to receive a
portion of the restricted shares of common stock of MK Rail held by MKO; and

         WHEREAS,  MK has made a motion (an "1145 Motion")  requesting  that the
Bankruptcy Court having  jurisdiction  over MK's bankruptcy  proceeding issue an
order  (an  "1145  Order")  providing  that  the  offering,  issuance,  sale and
distribution  by MKO of the common stock of MK Rail  qualifies for the exemption
(the "1145 Exemption"),  available under Section 1145(a) of the Bankruptcy Code,
from the  registration  requirements  of the Securities Act of 1933, as amended;
and

         WHEREAS, the Securities and Exchange Commission has stated that it will
not object to the 1145 Motion; and

         WHEREAS, the parties wish to amend the Agreement as set forth herein to
make certain changes thereto necessitated by the possibility that equity holders
of MK may  acquire  some  restricted  shares of  Common  Stock and that the 1145
Motion has been made;

         NOW  THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency  of which are  hereby  acknowledged,  the  parties  hereto  agree as
follows:

         1. The term "Rights Plan  Amendment" is hereby  amended and restated in
its entirety so it means the Second  Amendment to Rights  Agreement  dated as of
June 20, 1996 and the Third Amendment to Rights  Agreement of even date herewith
between MK Rail and Chase Mellon Shareholder Services, L.L.C., formerly known as
Chemical Mellon Shareholder Services, L.L.C.








         2. The  following  language is added at the end of the last sentence of
the definition of "Registrable Securities" in Section 1.1 of the Agreement:

         or in  "ordinary  trading  transactions"  within the meaning of Section
         1145(b)(1)  of the United  States  Bankruptcy  Code,  as  amended  (the
         "Bankruptcy Code").

         3. The reference to "creditors of MK" in the  definition of "Shares" in
Section 1.1 of the Agreement is hereby changed to a reference to "persons."

         4. The first  sentence of Section 8 of the Agreement is hereby  amended
in its entirety to read as follows:

         Notwithstanding  anything in this Agreement to the contrary,  no Holder
         may Transfer  any shares of Common  Stock to any Person,  except as set
         forth in the last paragraph of this Section 8, unless prior to any such
         Transfer  such Person has executed an agreement (in the form of Exhibit
         A hereto) to be bound, or has otherwise been effectively bound pursuant
         to the Plan, by the provisions of this Agreement.

         5. The last sentence of Section 8 of the  Agreement is hereby  amended,
restated and replaced in its entirety by the following sentences:

         MKO may  distribute  shares of Common  Stock to  equity  holders  of MK
         provided  that (a) the 1145 Order has been  issued and is in full force
         and effect and is not the  subject of a pending  appeal at the time the
         Common Stock is distributed  and (b) each equity holder  receiving such
         Common  Stock  has  executed  an  agreement  (in the form of  Exhibit A
         hereto) to be bound, or has otherwise been  effectively  bound pursuant
         to the Plan, by the provisions of this  Agreement.  No  distribution of
         Common  Stock to equity  holders or any other  party in a  distribution
         that qualifies for the 1145 Exemption shall excuse any party from or be
         deemed  to  constitute  a  release  of the  transfer  restrictions  and
         legending requirements set forth in this Section 8, except as set forth
         in the penultimate sentence of this paragraph,  and all Common Stock so
         distributed  shall after such  distribution be subject to said transfer
         restrictions  and legend  requirements  as well as all other  terms and
         conditions hereof. The foregoing transfer restrictions and legend shall
         be removed in  connection  with any sale of Common  Stock to the public
         pursuant to an effective registration statement or pursuant to Rule 144
         or any similar rule  promulgated by the Commission under the Securities
         Act,  or in  "ordinary  trading  transactions"  within  the  meaning of
         Section  1145(b)(1) of the Bankruptcy Code, in each case so long as the
         specific  identities  of the  Transferees  are not known to the Holders
         selling such shares  prior to such sale and so long as the  Transferees
         are not assigned  and do not receive any rights  under this  Agreement.
         The Company may also put the following  legend on certificates of stock
         held by Transferees of MKO and their  Transferees that are bound to the
         terms of this Agreement:

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                  THE SHARES OF STOCK  REPRESENTED BY THIS  CERTIFICATE HAVE NOT
                  BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933, AS AMENDED
                  (THE  "ACT"),  OR ANY STATE  SECURITIES  LAWS.  SUCH SHARES OF
                  STOCK  MAY  NOT  BE  TRANSFERRED  EXCEPT  (1)  PURSUANT  TO  A
                  REGISTRATION   STATEMENT  EFFECTIVE  UNDER  THE  ACT  AND  ANY
                  APPLICABLE STATE SECURITIES LAWS, (2) PURSUANT TO AN EXEMPTION
                  FROM  THE  REGISTRATION   REQUIREMENTS  OF  THE  ACT  AND  ANY
                  APPLICABLE  STATE SECURITIES LAW, OR (3) IF THE STOCK HAS BEEN
                  RECEIVED BY THE HOLDER HEREOF IN A DISTRIBUTION THAT QUALIFIES
                  FOR THE  EXEMPTION,  AVAILABLE  UNDER  SECTION  1145(a) OF THE
                  UNITED STATES  BANKRUPTCY  CODE,  AS AMENDED (THE  "BANKRUPTCY
                  CODE"),  TO  THE  REGISTRATION  REQUIREMENTS  OF THE  ACT,  IN
                  ORDINARY  TRADING  TRANSACTIONS  WITHIN THE MEANING OF SECTION
                  1145(b)(1) OF THE BANKRUPTCY CODE.

         6. All terms and provisions of the Agreement,  as amended hereby, shall
continue to be in full force and effect.


         IN WITNESS WHEREOF, the undersigned have hereunto set their hands as of
the day and year first set forth above.

                                         MK RAIL CORPORATION


                                         By:_______________________________

                                         Title:____________________________


                                         MORRISON KNUDSEN CORPORATION


                                         By:_______________________________

                                         Title:____________________________





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