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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G



                    Under the Securities Exchange Act of 1934
                             (Amendment No.__6___)*

                                Idex Corporation
 ------------------------------------------------------------------------------
                                (Name of Issuer)


                                  Common Stock
-------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    45167R104
                         ------------------------------
                                 (CUSIP Number)


Check the following box if a fee is being paid with this statement [ ]. (A fee
is not required only if the filing person: (1) has a previous statement on file
reporting beneficial ownership of more than five percent of the class of
securities described in Item 1; and (2) has filed no amendment subsequent
thereto reporting beneficial ownership of five percent or less of such
class.)(See Rule 13d-7).

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

SEC 1745 (10-88)



-------------------------                                    ------------------
  CUSIP NO.  45167R104                                       Page 2 of 5 Pages
-------------------------                                    ------------------

 ------------------------------------------------------------------------------
      NAMES OF REPORTING PERSONS.
1     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY).

      ARIEL CAPITAL MANAGEMENT, INC.
      # 36-3219058
------------------------------------------------------------------------------
      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 2                                                              (a) [_]
      Not Applicable                                            (b) [_]
------------------------------------------------------------------------------
      SEC USE ONLY
 3

------------------------------------------------------------------------------
      CITIZENSHIP OR PLACE OF ORGANIZATION
 4
      Illinois Corporation
------------------------------------------------------------------------------
                          SOLE VOTING POWER
                     5
     NUMBER OF
                          Ariel -  4,968,258
      SHARES       -----------------------------------------------------------
                          SHARED VOTING POWER
   BENEFICIALLY      6

     OWNED BY             Ariel -  0
                   -----------------------------------------------------------
       EACH               SOLE DISPOSITIVE POWER
                     7
    REPORTING             Ariel -  5,446,833

      PERSON       -----------------------------------------------------------
                          SHARED DISPOSITIVE POWER
       WITH          8
                          Ariel -   0
------------------------------------------------------------------------------
      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 9
                          Ariel -   5,449,208
------------------------------------------------------------------------------
      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
10
                     Not Applicable
------------------------------------------------------------------------------
      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
11
                     Ariel -    5,449,208 / 32,458,881 = 16.788%
------------------------------------------------------------------------------
      TYPE OF REPORTING PERSON *(SEE INSTRUCTIONS)
12
                     Ariel - IA
------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILING OUT!

*     This report is being made on behalf of John W. Rogers, Jr., Chairman and
Chief Executive Officer of Ariel Capital Management, Inc., who may be deemed to
have beneficial ownership of the securities of the issuer. Mr. Rogers disclaims
beneficial ownership of shares held by Ariel Capital Management, Inc.



                                                             Date:  12/31/02
                                                                    --------
                                                                 Page 3 of 5


Item 1(a)    Name of Issuer

             Idex Corporation
             -------------------------

Item 1(b)    Address of Issuer's Principal Executive Offices

             630 Dundee Road, Northbrook, IL 60062
             ------------------------------------------------------------

Item 2(a)    Name of Person Filing

             Ariel Capital Management, Inc.
             ------------------------------

Item 2(b)    Address of Principal Business Office:

             200 E. Randolph Drive, Suite 2900, Chicago, IL 60601
             ------------------------------------------------------------

Item 2(c)    Citizenship:

             an Illinois corporation
             -----------------------

Item 2(d)    Title of Class of Securities:

             Common Stock
             -------------

Item 2(e)    CUSIP Number

             45167R104
             ----------------

Item 3.      This statement is filed pursuant to 13d-1(b) or
             13d-2(b) and the person filing is an investment
             adviser registered under section 203 of the
             Investment Advisers Act of 1940.


Item 4.      Ownership.

             (a)  Amount beneficially owned:

                  (See Page 2, No. 9)
                  -------------------




                                                             Date:   12/31/02
                                                                     --------
                                                                  Page 4 of 5

             (b)  Percent of class:

                  (See Page 2, No. 11)
                  --------------------

             (c)  Number of shares as to which the person has:

                  (i)   Sole power to vote or to direct the vote
                        (See Page 2, No. 5)
                        -------------------

                  (ii)  Shared power to vote or to direct the vote
                        (See Page 2, No. 6)
                        -------------------

                  (ii)  Sole power to dispose or to direct the
                        disposition of  (See Page 2, No. 7)
                                         -------------------

                  (iii) Shared power to dispose or to direct the
                        disposition of  (See Page 2, No. 8)
                                        -------------------

Item 5.      Ownership of Five Percent or Less of a Class.

                  If this statement is being filed to report the fact that
             as of the date hereof the reporting person has ceased to be the
             beneficial owner of more than five percent of the class of
             securities, check the following: [_]

Item 6.      Ownership of More than Five Percent on Behalf of Another Person.

                  All securities reported upon this Schedule are owned by
             investment advisory clients of Ariel Capital Management, Inc.,
             no one of which to the knowledge of Ariel Capital Management, Inc.
             owns more than 5% of the class.


Item 7.      Identification and Classification of the Subsidiary Which Acquired
             the Security Being Reported on by the Parent Holding Company.

             Not Applicable
             --------------

Item 8.      Identification and Classification of Members of the Group.

             Not Applicable
             --------------

 Item 9.     Notice of Dissolution of a Group

             Not Applicable
             --------------



                                                              Date:   12/31/02
                                                                      --------
                                                                   Page 5 of 5

Item 10.     Certification

                  By signing below I certify that, to the best of my
             knowledge and belief, the securities referred to above were
             acquired and are held in the ordinary course of business and
             were not acquired and are not held for the purpose of or
             with the effect of changing or influencing the control of
             the issuer of the securities and were not acquired and are
             not held in connection with or as a participant in any
             transaction having that purpose or effect.


                                    SIGNATURE

     The undersigned hereby agree that this statement is being filed on behalf
of each of them and hereby certify, after reasonable inquiry and to the best of
their knowledge and belief, that the information set forth in this statement is
true, complete and correct.


                                        ARIEL CAPITAL MANAGEMENT, INC.


                                        By:    /s/  John W. Rogers, Jr.
                                             ----------------------------------
                                                    John W. Rogers, Jr.
                                                    Chief Investment Officer,
                                                    Chief Executive Officer,
                                                    and Chairman