-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 JSz+q6fJdoGV2YQkO6it8mk4qJ7LcGNcmRXRH1JA/dmiKRVEvDVIZewFTkcl1LNE
 SvBw0pvlnJGMMwwR4Ivg7w==

<SEC-DOCUMENT>0001260455-04-000001.txt : 20040720
<SEC-HEADER>0001260455-04-000001.hdr.sgml : 20040720
<ACCEPTANCE-DATETIME>20040720103153
ACCESSION NUMBER:		0001260455-04-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040716
FILED AS OF DATE:		20040720

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SWIFT BRUCE R
		CENTRAL INDEX KEY:			0001260455

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12068
		FILM NUMBER:		04921238

	MAIL ADDRESS:	
		STREET 1:		47603 HALYARD DRIVE
		CITY:			PLYMOUTH
		STATE:			MI
		ZIP:			48170

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			METALDYNE CORP
		CENTRAL INDEX KEY:			0000745448
		STANDARD INDUSTRIAL CLASSIFICATION:	MOTOR VEHICLE PARTS & ACCESSORIES [3714]
		IRS NUMBER:				382513957
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		47659 HALYARD DRIVE
		CITY:			PLYMOUTH
		STATE:			MI
		ZIP:			48170
		BUSINESS PHONE:		734-207-6200

	MAIL ADDRESS:	
		STREET 1:		47659 HALYARD DRIVE
		CITY:			PLYMOUTH
		STATE:			MI
		ZIP:			48170

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MASCOTECH INC
		DATE OF NAME CHANGE:	19930629

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MASCO INDUSTRIES INC
		DATE OF NAME CHANGE:	19930629
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-07-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000745448</issuerCik>
        <issuerName>METALDYNE CORP</issuerName>
        <issuerTradingSymbol>None</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001260455</rptOwnerCik>
            <rptOwnerName>SWIFT BRUCE R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O METALDYNE CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>47603 HALYARD DRIVE</rptOwnerStreet2>
            <rptOwnerCity>PLYMOUTH</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48170</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Driveline Group</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-07-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>145421</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-11-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>145421</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>145421</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The per share exercise price will be equal to the fair market value of the Company's Common Stock on July 16, 2004, as determined by the Compensation Committee of the Company's Board of Directors. The Compensation Committee will make this determination upon receipt of the Company's audited financial statements for the 2003 fiscal year and unaudited financial statements for the 1st &amp; 2nd quarters of fiscal year 2004.</footnote>
        <footnote id="F2">The option provides that 40% of the shares subject to the option will vest on July 16, 2004, and the remaining shares will vest in two equal annual installments beginning on July 16, 2005.</footnote>
        <footnote id="F3">On January 15, 2004, pursuant to a voluntary stock option exchange program, the Company cancelled all options previously granted to the reporting person. In exchange, the reporting person received the option reported herein and 3,827 restricted stock units.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Thomas M. Dono, Jr., Attorney-in-Fact</signatureName>
        <signatureDate>2004-07-20</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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