<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-09-23</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000097216</issuerCik>
        <issuerName>TEREX CORP</issuerName>
        <issuerTradingSymbol>TEX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001192692</rptOwnerCik>
            <rptOwnerName>WILKERSON ROBERT R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TEREX CORP</rptOwnerStreet1>
            <rptOwnerStreet2>500 POST RD EAST STE 320</rptOwnerStreet2>
            <rptOwnerCity>WESTPORT</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06880</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Pres. TerexAerialWorkPlatform</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.01</value>
            </securityTitle>
            <transactionDate>
                <value>2003-09-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>66000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.9037</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>991567</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Sold pursuant to a written plan for trading securities under Rule 10b5-1.</footnote>
        <footnote id="F2">Sold at various prices ranging from $19.48 to $20.22 as follows: (shares at dollar price per share) - 3800 @ 19.48; 800 @ 19.49; 1500 @ 19.58; 500 @ 19.62; 700 @ 19.66; 1500 @ 19.67; 2100 @ 19.68; 2000 @ 19.70; 400 @ 19.71; 3300 @ 19.72; 200 @ 19.73; 100 @ 19.76; 1500 @ 19.77; 1400 @ 19.79; 5500 @ 19.80; 300 @ 19.81; 700 @ 19.82; 500 @ 19.83; 600 @ 19.85; 200 @ 19.88; 7400 @ 19.90; 900 @ 19.92; 400 @ 19.93; 500 @ 19.94; 1600 @ 19.96; 500 @ 19.97; 400 @ 19.98; 3300 @ 20.00; 600 @ 20.02; 900 @ 20.03; 2200 @ 20.04; 300 @ 20.05; 300 @ 20.06; 500 @ 20.07; 200 @ 20.08; 1000 @ 20.09; 2300 @ 20.10; 100 @ 20.11; 1300 @ 20.12; 2200 @ 20.13; 3200 @ 20.14; 200 @ 20.15; 300 @ 20.17; 700 @ 20.18; 1900 @ 20.19; 4800 @ 20.20; 100 @ 20.21; 300 @ 20.22.</footnote>
        <footnote id="F3">Represents shares beneficially owned as of September 23, 2003.</footnote>
        <footnote id="F4">Includes 66,502 shares by Wilkerson Limited Partnership.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/  ROBERT R. WILKERSON</signatureName>
        <signatureDate>2003-09-24</signatureDate>
    </ownerSignature>

</ownershipDocument>
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X0201
4
2003-09-23
0
0000097216
TEREX CORP
TEX
0001192692
WILKERSON ROBERT R
C/O TEREX CORP
500 POST RD EAST STE 320
WESTPORT
CT
06880
0
1
0
0
Pres. TerexAerialWorkPlatform
Common Stock, par value $.01
2003-09-23
4
S
0
66000
19.9037
D
991567
D
Sold pursuant to a written plan for trading securities under Rule 10b5-1.
Sold at various prices ranging from $19.48 to $20.22 as follows: (shares at dollar price per share) - 3800 @ 19.48; 800 @ 19.49; 1500 @ 19.58; 500 @ 19.62; 700 @ 19.66; 1500 @ 19.67; 2100 @ 19.68; 2000 @ 19.70; 400 @ 19.71; 3300 @ 19.72; 200 @ 19.73; 100 @ 19.76; 1500 @ 19.77; 1400 @ 19.79; 5500 @ 19.80; 300 @ 19.81; 700 @ 19.82; 500 @ 19.83; 600 @ 19.85; 200 @ 19.88; 7400 @ 19.90; 900 @ 19.92; 400 @ 19.93; 500 @ 19.94; 1600 @ 19.96; 500 @ 19.97; 400 @ 19.98; 3300 @ 20.00; 600 @ 20.02; 900 @ 20.03; 2200 @ 20.04; 300 @ 20.05; 300 @ 20.06; 500 @ 20.07; 200 @ 20.08; 1000 @ 20.09; 2300 @ 20.10; 100 @ 20.11; 1300 @ 20.12; 2200 @ 20.13; 3200 @ 20.14; 200 @ 20.15; 300 @ 20.17; 700 @ 20.18; 1900 @ 20.19; 4800 @ 20.20; 100 @ 20.21; 300 @ 20.22.
Represents shares beneficially owned as of September 23, 2003.
Includes 66,502 shares by Wilkerson Limited Partnership.
/s/  ROBERT R. WILKERSON
2003-09-24