AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 8, 1998
                                              REGISTRATION NO. 333-46381
===========================================================================
                     SECURITIES AND EXCHANGE COMMISSION
                           WASHINGTON, D.C. 20549
                       ------------------------------
                       POST EFFECTIVE AMENDMENT NO. 1
                                     TO
                                  FORM S-4
                           REGISTRATION STATEMENT
                                   UNDER
                         THE SECURITIES ACT OF 1933
                       ------------------------------
                              SPX CORPORATION
           (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

        DELAWARE                       3429                      38-1016240
    (STATE OR OTHER             (PRIMARY STANDARD              (IRS EMPLOYER
    JURISDICTION OF         INDUSTRIAL CLASSIFICATION       IDENTIFICATION NO.)
    INCORPORATION OR              CODE NUMBER)
     ORGANIZATION)
                       ------------------------------
                          700 TERRACE POINT DRIVE
                             MUSKEGON, MI 49443
                               (616) 724-5000
            (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
     INCLUDING AREA CODE, OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                       ------------------------------
                        CHRISTOPHER J. KEARNEY, ESQ.
               VICE PRESIDENT, SECRETARY AND GENERAL COUNSEL
                              SPX CORPORATION
                          700 TERRACE POINT DRIVE
                             MUSKEGON, MI 49443
                               (616) 724-5000
                         (NAME, ADDRESS, INCLUDING
            ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                           OF AGENT FOR SERVICE)

                       ------------------------------
                                 COPIES TO:
                            AVIVA DIAMANT, ESQ.
                  FRIED, FRANK, HARRIS, SHRIVER & JACOBSON
                             ONE NEW YORK PLAZA
                          NEW YORK, NEW YORK 10004
                               (212) 859-8000

                       ------------------------------

     APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO PUBLIC: As soon
as practicable after the Registration Statement becomes effective.

     If the securities being registered on this Form are being offered in
connection with the formation of a holding company and there is compliance
with General Instruction G, check the following box. |_|

                       ------------------------------

     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION  STATEMENT ON SUCH DATE
OR  DATES AS MAY BE  NECESSARY  TO  DELAY  ITS  EFFECTIVE  DATE  UNTIL  THE
REGISTRANT SHALL FILE A FURTHER  AMENDMENT WHICH  SPECIFICALLY  STATES THAT
THIS REGISTRATION STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE
WITH SECTION 8(A) OF THE SECURITIES  ACT OF 1933 OR UNTIL THE  REGISTRATION
STATEMENT  SHALL BECOME  EFFECTIVE ON SUCH DATE AS THE  COMMISSION,  ACTING
PURSUANT TO SAID SECTION 8(A), MAY DETERMINE.

===========================================================================

     The Registrant  hereby  withdraws from  registration  those 29,948,407
shares of its Common Stock, par value $10.00,  ("SPX Common Stock") and the
associated  rights  to  Purchase  Preferred  Stock  previously   registered
pursuant to this Registration  Statement.  The Registrant has withdrawn its
offer to  exchange  each share of common  stock,  par value $1.00 of Echlin
Inc.  for $12.00 and .4796 share of SPX Common  Stock,  prior to any of the
shares registered pursuant to this Registration  Statement being exchanged.
The Registration  Statement is hereby amended,  as appropriate,  to reflect
the deregistration of such shares.


                                 SIGNATURES

     PURSUANT  TO THE  REQUIREMENTS  OF THE  SECURITIES  ACT OF  1933,  THE
REGISTRANT HAS DULY CAUSED THIS REGISTRATION  STATEMENT TO BE SIGNED ON ITS
BEHALF BY THE UNDERSIGNED,  THEREUNTO DULY  AUTHORIZED,  IN THE CITY OF NEW
YORK, STATE OF NEW YORK ON THIS 8th DAY OF MAY 1998.

                                          SPX Corporation

                                          By:   /s/ Christopher J. Kearney
                                                --------------------------
                                                Christopher J. Kearney
                                                Vice President, Secretary
                                                and General Counsel


     PURSUANT  TO THE  REQUIREMENTS  OF THE  SECURITIES  ACT OF 1933,  THIS
REGISTRATION  STATEMENT  HAS BEEN  SIGNED  BY THE  FOLLOWING  PERSONS  (WHO
INCLUDE ALL MEMBERS OF THE BOARD OF DIRECTORS) IN THE CAPACITIES AND ON THE
DATE INDICATED.

        SIGNATURE                    TITLE                      DATE
        ---------                    -----                      ----

          *                       Director                   May 8, 1998
- ---------------------------
          *                       Director                   May 8, 1998
- ---------------------------
          *                       Chairman, President and    May 8, 1998
- ---------------------------       Chief Executive Officer
                                  and Director

          *                       Director                   May 8, 1998
- ---------------------------
          *                       Director                   May 8, 1998
- ---------------------------
          *                       Director                   May 8 , 1998
- ---------------------------
          *                       Director                   May 8 , 1998
- ---------------------------
          *                       Director                   May 8, 1998
- ---------------------------
          *                       Director                   May 8, 1998
- ---------------------------
          *                       Patrick J. O'Leary         May 8, 1998
- ---------------------------
                                  (Principal Financial
                                  Officer)

          *                       Kenneth C. Dow             May 8, 1998
- ---------------------------       (Principal Accounting
                                  Officer)




*By  /s/ Christopher J. Kearney
     --------------------------
         Christopher J. Kearney
         As Attorney-In-Fact