In some VW and Audi 01M, 01N and 01P units, you may find after installing the Sonnax oversized TCC apply valve kit119940-04Kthat the TCC apply valve sticks or doesn't drop all the way into the bore without excessive force. Using Sonnax bore sizing tool 119940-BST resizes the bore and gives you the finish and roundness you need to allow the valve to move freely.