SEAT Workshop Service and Repair Manuals

Removing and installing mechatronic unit for dual clutch gearbox -J743- (gearbox removed) Always make sure that no dirt can enter an »open« gearbox. In particular, dirt entering an »exposed«mechatronic unit for dual clutch gearbox -J743- or oil pump can lead to gearbox failure. Please also refer to the notes on the oil filter change regarding »dirty oil« → Chapter. Removing mechatronic unit To gearbox manufacture date „20 September 2004“, gearboxes were constructed with 2 plugs.

–  Remove bolt -A- near pendulum support. There is a black plastic overflow tube in the hole (with an interior 8 mm nut, tightening torque: 3 Nm) is located behind the plug. Its length determines the oil level in the gearbox. –  Remove this oil pipe. –  Drain oil. Please also refer to the notes on the oil filter change regarding »dirty oil« → Chapter. –  Screw in overflow tube again, tightening torque: 3 Nm.

–  Remove filter if necessary. Often, doubts arise as to whether the filter must be renewed or not. The notes on the oil filter change can help you in reaching this decision → Chapter.

–  Insert new filter with shoulder downwards and tighten cover to 20 Nm. –  Following repair work, it is not necessary to change filter again when filling oil.

–  Remove both -covers-. »Small« cover of oil pump and bolts of »large« cover must always be renewed. Likewise, seal of »large« cover must be renewed.

Before touching mechatronic unit, touch an earthed object → Chapter.

–  Release connector -1- of gearbox input speed sender -G182- and oil temperature sender in multi-plate clutch -G509- using release tool -T10465- and pull connector off.

–  First pull line out of lower clip -arrow I-. –  Then remove it from second clip -arrow II- and lay to side. Do not kink line.

–  Remove -securing bolts- diagonally. Start with bolt -1-. All 10 -securing bolts- must be renewed.

–  Remove mechatronic unit for dual clutch gearbox -J743-. When handling mechatronic unit, pay special attention to the »long« sender arm.   Caution DO NOT lift the mechatronic unit by the sender »arm« or put down the unit so it rests on the sender arm.

If »arm« is damaged, mechatronic unit must be renewed. –  Put down the mechatronic unit correctly.

Put down the mechatronic unit correctly. Installing mechatronic unit   Caution DO NOT lift the mechatronic unit by the sender »arm« or put down the unit so it rests on the sender arm.

If »arm« is damaged, mechatronic unit must be renewed.

–  Before installation of mechatronic unit, make certain that gearbox input speed sender -G182- with oil temperature sender in multi-plate clutch -G509- is installed.

–  Renew both -O-rings- if you reinstall the »old« mechatronic unit. (Of course a »new« mechatronic unit already has »new« seals.) –  Moisten O-rings with dual clutch gearbox oil.

–  Carefully set mechatronic unit on dowel pins -arrow-. Ensure that »sender arm« locates in its -fitting position-. –  Do not pinch wiring. Take care not to trap the cable.

All 10 -securing bolts- must be renewed. –  First start all -securing bolts-»by hand«. –  Then tighten all 10 -bolts- diagonally to 5 Nm. After this, turn a further 90° in same sequence. Start with bolt -1-.

–  First press wiring for gearbox input speed sender -G182- with oil temperature sender in multi-plate clutch -G509- into clip -II-. Then into clip -I-. –  Press connection onto mechatronic unit. »Small« cover of oil pump and bolts of »large« cover must always be renewed.

Likewise, -seal- of »large«-cover- must be renewed. –  Tighten cover bolts »diagonally« to 10 Nm. After installing gearbox –  Check oil level and top up → Chapter. –  Perform basic setting.