content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <!-- Field: Pseudo-Tag; ID: Name; Data: Stockbridge Partners LLC -->
            <cik>0001505183</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001260221</issuerCik>
        <issuerName>TransDigm Group INC</issuerName>
        <secFileNumber>001-32833</secFileNumber>
        <issuerAddress>
          <com:street1>1301 East 9th Street, Suite 3000</com:street1>
          <com:city>Cleveland</com:city>
          <com:stateOrCountry>OH</com:stateOrCountry>
          <com:zipCode>44114</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>216-706-2960</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Stockbridge Partners LLC</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>May be deemed affiliate.</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Glen Eagle Wealth, LLC</name>
          <address>
            <com:street1>4428-C Route 27</com:street1>
            <com:city>Kingston</com:city>
            <com:stateOrCountry>NJ</com:stateOrCountry>
            <com:zipCode>08528</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>25000</noOfUnitsSold>
        <aggregateMarketValue>24813000.00</aggregateMarketValue>
        <noOfUnitsOutstanding>55314104</noOfUnitsOutstanding>
        <approxSaleDate>12/12/2023</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>04/25/2007</acquiredDate>
        <natureOfAcquisitionTransaction>Open market purchases</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Open market purchases</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>25000</amountOfSecuritiesAcquired>
        <paymentDate>04/25/2007</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Stockbridge Partners LLC</name>
          <address>
            <com:street1>200 CLARENDON STREET</com:street1>
            <com:street2>35TH FLOOR</com:street2>
            <com:city>BOSTON</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02116</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>09/12/2023</saleDate>
        <amountOfSecuritiesSold>2967</amountOfSecuritiesSold>
        <grossProceeds>2612341.73</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Stockbridge Partners LLC</name>
          <address>
            <com:street1>200 CLARENDON STREET</com:street1>
            <com:street2>35TH FLOOR</com:street2>
            <com:city>BOSTON</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02116</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>11/16/2023</saleDate>
        <amountOfSecuritiesSold>20000</amountOfSecuritiesSold>
        <grossProceeds>19775110.00</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Stockbridge Partners LLC</name>
          <address>
            <com:street1>200 CLARENDON STREET</com:street1>
            <com:street2>35TH FLOOR</com:street2>
            <com:city>BOSTON</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02116</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>11/17/2023</saleDate>
        <amountOfSecuritiesSold>46700</amountOfSecuritiesSold>
        <grossProceeds>44713111.14</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Stockbridge Partners LLC</name>
          <address>
            <com:street1>200 CLARENDON STREET</com:street1>
            <com:street2>35TH FLOOR</com:street2>
            <com:city>BOSTON</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02116</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>11/20/2023</saleDate>
        <amountOfSecuritiesSold>39558</amountOfSecuritiesSold>
        <grossProceeds>38181338.09</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Stockbridge Partners LLC</name>
          <address>
            <com:street1>200 CLARENDON STREET</com:street1>
            <com:street2>35TH FLOOR</com:street2>
            <com:city>BOSTON</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02116</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>11/21/2023</saleDate>
        <amountOfSecuritiesSold>23201</amountOfSecuritiesSold>
        <grossProceeds>22503257.77</grossProceeds>
      </securitiesSoldInPast3Months>
      <remarks>Stockbridge Partners LLC is deemed to be the beneficial owner of the Common Stock held through a separate managed account and through Stockbridge Fund, L.P. Regarding the "Securities To Be Sold" Table, the dates of acquisition and payment of the Common Stock varied, commencing on the date reported in the Table. Stockbridge Partners LLC is signing this form on behalf of the separate managed account and Stockbridge Fund, L.P.</remarks>
      <noticeSignature>
        <noticeDate>12/12/2023</noticeDate>
        <signature>STOCKBRIDGE PARTNERS LLC, By: BPSP, L.P., its Managing Member, By: Berkshire Partners Holdings LLC, its General Partner, Kenneth S. Bring, its M.D.</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 6674}]
text: 144
  0001505183
  XXXXXXXX
  LIVE
  0001260221
  TransDigm Group INC
  001-32833
  1301 East 9th Street, Suite 3000
  Cleveland
  OH
  44114
  216-706-2960
  Stockbridge Partners LLC
  May be deemed affiliate.
  Common Stock
  Glen Eagle Wealth, LLC
  4428-C Route 27
  Kingston
  NJ
  08528
  25000
  24813000.00
  55314104
  12/12/2023
  NYSE
  Common Stock
  04/25/2007
  Open market purchases
  Open market purchases
  N
  25000
  04/25/2007
  Cash
  N
  Stockbridge Partners LLC
  200 CLARENDON STREET
  35TH FLOOR
  BOSTON
  MA
  02116
  Common Stock
  09/12/2023
  2967
  2612341.73
  Stockbridge Partners LLC
  200 CLARENDON STREET
  35TH FLOOR
  BOSTON
  MA
  02116
  Common Stock
  11/16/2023
  20000
  19775110.00
  Stockbridge Partners LLC
  200 CLARENDON STREET
  35TH FLOOR
  BOSTON
  MA
  02116
  Common Stock
  11/17/2023
  46700
  44713111.14
  Stockbridge Partners LLC
  200 CLARENDON STREET
  35TH FLOOR
  BOSTON
  MA
  02116
  Common Stock
  11/20/2023
  39558
  38181338.09
  Stockbridge Partners LLC
  200 CLARENDON STREET
  35TH FLOOR
  BOSTON
  MA
  02116
  Common Stock
  11/21/2023
  23201
  22503257.77
  Stockbridge Partners LLC is deemed to be the beneficial owner of the Common Stock held through a separate managed account and through Stockbridge Fund, L.P. Regarding the "Securities To Be Sold" Table, the dates of acquisition and payment of the Common Stock varied, commencing on the date reported in the Table. Stockbridge Partners LLC is signing this form on behalf of the separate managed account and Stockbridge Fund, L.P.
  12/12/2023
  STOCKBRIDGE PARTNERS LLC, By: BPSP, L.P., its Managing Member, By: Berkshire Partners Holdings LLC, its General Partner, Kenneth S. Bring, its M.D.