-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 V2vxP+mFTIujrKqRZBe9SE3UPYrq/ocUl24Lbi3aauHlFl3X+N2jvKzqsTbZUBUw
 CgO1/OR+xyNdBX3Tri5uLQ==

<SEC-DOCUMENT>0000775158-11-000007.txt : 20110202
<SEC-HEADER>0000775158-11-000007.hdr.sgml : 20110202
<ACCEPTANCE-DATETIME>20110202171938
ACCESSION NUMBER:		0000775158-11-000007
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110201
FILED AS OF DATE:		20110202
DATE AS OF CHANGE:		20110202

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DONNELLY RICHARD M
		CENTRAL INDEX KEY:			0001207729

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31371
		FILM NUMBER:		11567500

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OSHKOSH CORP
		CENTRAL INDEX KEY:			0000775158
		STANDARD INDUSTRIAL CLASSIFICATION:	MOTOR VEHICLES & PASSENGER CAR BODIES [3711]
		IRS NUMBER:				390520270
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		2307 OREGON ST
		STREET 2:		P O BOX 2566
		CITY:			OSHKOSH
		STATE:			WI
		ZIP:			54903
		BUSINESS PHONE:		920 235 9151

	MAIL ADDRESS:	
		STREET 1:		2307 OREGON ST P O BOX 2566
		STREET 2:		2307 OREGON ST P O BOX 2566
		CITY:			OSHKOSH
		STATE:			WI
		ZIP:			54903

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OSHKOSH TRUCK CORP
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-02-01</periodOfReport>

    <issuer>
        <issuerCik>0000775158</issuerCik>
        <issuerName>OSHKOSH CORP</issuerName>
        <issuerTradingSymbol>OSK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001207729</rptOwnerCik>
            <rptOwnerName>DONNELLY RICHARD M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OSHKOSH CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>2307 OREGON STREET</rptOwnerStreet2>
            <rptOwnerCity>OSHKOSH</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>54902-7062</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1350</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11536.76</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>38.46</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2011-02-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-02-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock granted to Reporting Person on February 1, 2011, subject to certain transfer restrictions.</footnote>
        <footnote id="F2">Option (right to buy) granted pursuant to the Company's Stock Plan.</footnote>
        <footnote id="F3">Options vest in one-third (1/3) annual increments commencing on 2/1/2012.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Bryan J. Blankfield, for Richard M. Donnelly</signatureName>
        <signatureDate>2011-02-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----