EXHIBIT 5.1


                           Gardner, Carton & Douglas
                      321 North Clark Street, Suite 3400
                            Chicago, Illinois 60610


                              September 10, 2001


SPX Corporation
700 Terrace Point Drive
Muskegon, Michigan 49443

     Re:  Registration Statement on Form S-8
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Ladies and Gentlemen:

     We have acted as counsel to SPX Corporation, a Delaware corporation (the
"Corporation"), in connection with the filing of a Registration Statement on
Form S-8 by the Corporation under the Securities Act of 1933, as amended (the
"Registration Statement"), which Registration Statement registers 5,000,000
shares of Common Stock, par value $10 per share (the "Common Stock"), reserved
for issuance under the Corporation's 1992 Stock Compensation Plan (the "Plan").
In that capacity, we have reviewed the Certificate of Incorporation and Bylaws
of the Corporation, both as amended to date, the Registration Statement, the
Plan, originals or copies of corporate records reflecting the corporate action
taken by the Corporation in connection with the approval of the Plan and the
issuance of the Common Stock under the Plan and such other instruments as we
have deemed necessary for the issuance of this opinion.

     Based upon the foregoing, we are of the opinion that the Common Stock to be
offered under the Plan has been duly authorized by all requisite action on the
part of the Corporation and, when issued in accordance with the terms and
conditions of the Plan, will be legally issued, fully paid and non-assessable.

     We consent to the filing of this opinion as an exhibit to the Registration
Statement.  In giving this consent, we do not admit that we are within the
category of persons whose consent is required by Section 7 of the Securities Act
of 1933, as amended.

                                               Very truly yours,



                                           /s/ GARDNER, CARTON & DOUGLAS