Bore wear is common in VW/Audi 01J units due to contamination and high system pressure. Any unit with a worn clutch control valve and/or bore can show clutch chatter on forward or reverse engagement and clutch friction failure and overheat. These symptoms are caused by the loss of fluid pressure to the forward or reverse clutches due to excessive wear, allowing critical hydraulic pressure to leak to adjacent circuits or to the sump. OE function and performance can be expected after installing the Sonnax oversized clutch control (KSV) valve kit 33741B-03K