-----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,
 WtV6d5f+9AmsVi40Lli5BkHeTovZ7RehYHKkZlVAV6nZ2rngdyN03m27a2pAHN48
 Bo/N/3tl2m7jDVfPvoK6kw==

<SEC-DOCUMENT>0001140361-03-002094.txt : 20030619
<SEC-HEADER>0001140361-03-002094.hdr.sgml : 20030619
<ACCEPTANCE-DATETIME>20030619171447
ACCESSION NUMBER:		0001140361-03-002094
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030618
FILED AS OF DATE:		20030619

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RIDGE GARRY O
		CENTRAL INDEX KEY:			0001191649

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06936
		FILM NUMBER:		03750656

	MAIL ADDRESS:	
		STREET 1:		1061 CUDAHY PL
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WD 40 CO
		CENTRAL INDEX KEY:			0000105132
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS CHEMICAL PRODUCTS [2890]
		IRS NUMBER:				951797918
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		1061 CUDAHY PL
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110
		BUSINESS PHONE:		6192751400

	MAIL ADDRESS:	
		STREET 1:		1061 CUDAHY PLACE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-06-18</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000105132</issuerCik>
        <issuerName>WD 40 CO</issuerName>
        <issuerTradingSymbol>wdfc</issuerTradingSymbol>
</issuer>
<reportingOwner>
<reportingOwnerId>
            <rptOwnerCik>0001191649</rptOwnerCik>
            <rptOwnerName>RIDGE GARRY O</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>President &amp; CEO</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeSecurity>
<securityTitle>
<value>Common Stock</value>
</securityTitle>
<transactionDate>
<value>2003-06-18</value>
</transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F1"/>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>6809</value>
</transactionShares>
<transactionValue>
<value>18.084</value>
</transactionValue>
<transactionAcquiredDisposedCode>
<value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>17645.758</value>
<footnoteId id="F2"/>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeSecurity>
<nonDerivativeSecurity>
<securityTitle>
<value>Common Stock</value>
</securityTitle>
<transactionDate>
<value>2003-06-18</value>
</transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F1"/>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>6809</value>
</transactionShares>
<transactionValue>
<value>28.20</value>
</transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>10836.758</value>
<footnoteId id="F2"/>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeSecurity>
<derivativeSecurity>
<securityTitle>
<value>Non-Qualified Stock Option</value>
</securityTitle>
<conversionOrExercisePrice>
<value>18.084</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-06-18</value>
</transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F1"/>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>6809</value>
</transactionShares>
<transactionValue>
<value>00.00</value>
</transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2002-04-27</value>
</exerciseDate>
<expirationDate>
<value>2011-04-27</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>6809</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>176171</value>
<footnoteId id="F3"/>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeSecurity>
<footnotes>
<footnote id="F1">Transaction pursuant to trading plan adopted pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934.</footnote>
<footnote id="F2">Total includes 877 shares held in WD-40 Company Profit Sharing Plan &amp;quot;Company Stock Fund&amp;quot; account; estimated number of shares based upon equivalent value of units held.</footnote>
<footnote id="F3">Incentive Stock Option (&amp;quot;ISO&amp;quot;) to buy 3,980 shares exercisable 01/01/98 at $21.188 expires 09/25/05; ISO to buy 7,000 shares exercisable 01/01/00 at $23.00 expires 09/23/06; ISO to buy 16,000 shares exercisable (2,222 shares exercisable 01/01/00, 3,149 shares exercisable 01/01/01, 3,149 shares exercisable 01/01/02, 3,149 shares exercisable 01/01/03, 3,149 shares exercisable 01/01/04, and 1,182 shares exercisable 01/01/05); Non Qualified Stock Option (&amp;quot;NQSO&amp;quot;)to buy 16,000 shares exercisable 09/29/99 at $23.06 expires 09/29/08; NQSO to buy 20,000 shares exercisable 09/28/00 at $23.50 expires 09/28/09; NQSO to buy 40,000 shares exercisable 09/26/01 at $20.813 expires 09/26/10; NQSO to buy 13,191 shares exercisable 04/27/02 at $18.084 expires 04/27/11; NQSO to buy 30,000 shares exercisable 09/25/02 at $20.75 expires 90/25/11; NQSO to buy 30,000 shares exercisable (10,000 shares exercisable 09/24/03, 10,000 shares exercisable 09/24/04, and 10,000 shares exerci
sable 09/24/05) at $27.56 expires 09/24/12.</footnote>
</footnotes>
<ownerSignature>
<signatureName>Garry O. Ridge</signatureName>
<signatureDate>2003-06-18</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
