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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001209191-04-001267.txt : 20040106
<SEC-HEADER>0001209191-04-001267.hdr.sgml : 20040106
<ACCEPTANCE-DATETIME>20040106120034
ACCESSION NUMBER:		0001209191-04-001267
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031130
FILED AS OF DATE:		20040106

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GENCORP INC
		CENTRAL INDEX KEY:			0000040888
		STANDARD INDUSTRIAL CLASSIFICATION:	FABRICATED RUBBER PRODUCTS, NEC [3060]
		IRS NUMBER:				340244000
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			1130

	BUSINESS ADDRESS:	
		STREET 1:		HIGHWAY 50 & AEROJET ROAD
		CITY:			RANCHO CORDOVA
		STATE:			CA
		ZIP:			95670
		BUSINESS PHONE:		9163554000

	MAIL ADDRESS:	
		STREET 1:		HIGHWAY 50 & AEROJET ROAD
		CITY:			RANCHO CORDOVA
		STATE:			CA
		ZIP:			95670

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GENERAL TIRE & RUBBER CO
		DATE OF NAME CHANGE:	19840330

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WOLFE ROBERT A
		CENTRAL INDEX KEY:			0001212535

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-01520
		FILM NUMBER:		04508605

	BUSINESS ADDRESS:	
		STREET 1:		C/O GENCORP INC.,
		STREET 2:		P.O. BOX 537012
		CITY:			SACRAMENTO
		STATE:			CA
		ZIP:			95853-7012
		BUSINESS PHONE:		9163518515

	MAIL ADDRESS:	
		STREET 1:		C/O GENCORP INC.,
		STREET 2:		P.O. BOX 537012
		CITY:			SACRAMENTO
		STATE:			CA
		ZIP:			95853-7012
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>doc5.xml
<DESCRIPTION>FORM 5 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>5</documentType><periodOfReport>2003-11-30</periodOfReport><notSubjectToSection16>1</notSubjectToSection16>
    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000040888</issuerCik>
        <issuerName>GENCORP INC</issuerName>
        <issuerTradingSymbol>GY</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001212535</rptOwnerCik>
            <rptOwnerName>WOLFE ROBERT A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>HIGHWAY 50 &amp; AEROJET ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RANCHO CORDOVA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95670</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Chairman</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2002-02-27</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value>L</value></transactionTimeliness><transactionAmounts><transactionShares><value>40500.0000</value><footnoteId id="F1" /></transactionShares><transactionPricePerShare><footnoteId id="F2" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>189041.2934</value><footnoteId id="F3" /></sharesO
wnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-11-30</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>5774.0400</value><footnoteId id="F4" /></transactionShares><transactionPricePerShare><footnoteId id="F2" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13100.7800</value></sharesOwnedFollowingTransaction></postTransactionAmounts><owne
rshipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Plan Trust</value></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Phantom Stock Unit</value></securityTitle><conversionOrExercisePrice><footnoteId id="F5" /></conversionOrExercisePrice><transactionDate><value>2003-11-30</value></transactionDate><deemedExecutionDate><footnoteId id="F6" /></deemedExecutionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>1202.1870</value><footnoteId id="F7" /></transactionShares><transactionPricePerShare><footnoteId id="F10" /></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmou
nts><exerciseDate><footnoteId id="F8" /></exerciseDate><expirationDate><footnoteId id="F9" /></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1202.1870</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>47867.4870</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Plan</value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Performance based restricted stock forfeited due to failure to achieve threshold FY2002 growth target.</footnote><footnote id="F2">Due to the nature of this transaction, the Price of the Non-Derivative Security is not relevant to transaction. </footnote><footnote id="F3">For any exempt transactions, the software requires that a balance 
footnote be attached to the reportable transaction on the form, even if it does not relate to the reportable transaction.  The balance footnote will explain any exempt transaction which is not reportable, yet the addition of those shares must be recognized in the computer computation of total shares.  In this case the common stock balance has been updated with 4795.3098 shares acquired on 2-28-02, 5-31-02, 8-30-02, 11-29-02, 2-28-03, 5-30-03, 8-29-03 and 11-28-03 under the GenCorp Dividend Reinvestment Program.</footnote><footnote id="F4">Shares held in the GenCorp Retirement Savings Plan Trust ("Plan Trust") as of November 28, 2003 per the Plan Administrator's records.  The number of shares reported is calculated by dividing the dollar value of the participant's account by the closing stock price printed in the New York Stock Exchange Composite Transactions in the Wall Street Journal on the day reported above.  This calculation yields only the approximate number of shares in the participant's account becaus
e the cash component in the Plan Trust (target 2%) is allocated to each participant's account on a pro rata basis, and the cash component varies based on overall activity of all participants in the Plan Trust.

</footnote><footnote id="F5">Due to the nature of this transaction, the Conversion or Exercise Price of Derivative Security is not relevant to this transaction. </footnote><footnote id="F6">Due to the nature of this transaction, the Execution Date is not relevant to this transaction. </footnote><footnote id="F7">Phantom stock units acquired under the Deferred Bonus Plan.  Includes phantom stock units acquired through reinvestment of dividends on 2-28-02, 5-31-02, 8-30-02 and 11-29-02, 2-28-03, 5-30-03, 8-29-03, and 11-28-03.</footnote><footnote id="F8">Due to the nature of this transaction, the Date Exercisable is not relevant to this transaction. </footnote><footnote id="F9">Due to the nature of this transaction, the Expiration Date is not relevant to this transaction. </footnote><footnote id="F10">Due to the nature of this transaction, the Price of the Derivative Security is not relevant to this transaction.</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>Mark A. Whitney as attorney
- -in-fact for Robert A. Wolfe</signatureName><signatureDate>2004-01-06</signatureDate></ownerSignature></ownershipDocument>

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