Removing and installing mechatronic unit for dual clutch gearbox J743 with gearbox installed — AUDI

Removing and installing
mechatronic unit for dual clutch gearbox
J743
with gearbox installed
Special tools and workshop equipment required
Vehicle diagnostic tester
Used oil collection and extraction unit
V.A.G 1782
Engine bung set
VAS 6122
Drip tray for workshop hoist
VAS 6208
Guide pin
T10406
Assembly lever
T10407
Removing
Caution
Do not run engine or tow vehicle with
mechatronic unit for dual clutch gearbox
J743
removed or when there is no gear oil in the gearbox.
Note
Please refer to
Chapter
“
Repair instructions
”
.
Please refer to
Chapter
“
Rules for cleanliness
”
.
Observe notes on dual clutch gearbox 0AM
Chapter
.
The clutch is self-adjusting. Shocks can affect the adjusting mechanism. Even if the mechatronic unit has been removed, suddenly pulling out the
assembly lever
T10407
from under the engaging levers can have a negative effect on the adjusting mechanism.
A new mechatronic unit is supplied with the correct oil filling. Do not drain oil.
After removal, the used mechatronic unit is sent back with its oil in. The mechatronic unit remains filled with oil.
Remove noise insulation
1
General body repairs, exterior
Rep. gr.
66
Noise insulation; Exploded view - noise insulation
.
Remove noise insulation frame
arrow
with noise insulation (rear)
General body repairs, exterior
Rep. gr.
50
Lock carrier; Exploded view - lock carrier
.
Note
The vehicle diagnostic tester moves all gear actuators into
“neutral”
position.
In this position, insert
assembly lever
T10407
between engaging lever and gearbox housing. This makes it possible to remove load from the plungers of the mechatronic unit so that they can be removed by hand from the retainers on the engaging levers.
Shift selector lever into position
“P”
.
Connect vehicle diagnostic tester and switch on ignition.
Select the following menu items:
Guided Functions
02 - 7-speed dual clutch gearbox
Basic setting neutral
Switch off ignition.
WARNING
Risk of scalding from hot steam and hot coolant.
The cooling system is under pressure when the engine is hot.
Cover filler cap on expansion tank with a cloth and open carefully to release pressure.
Open filler cap on expansion tank.
Lift retaining clip
1
and loosen hose clip
2
to remove air hose.
Unplug electrical connector
2
for
radiator outlet coolant temperature sender
G83
.
Note
Catch escaping coolant in a clean container for disposal or re-use.
Detach coolant hose (bottom)
1
from radiator (lift retaining clip).
Place
drip tray for workshop hoist
VAS 6208
under the engine.
Caution
Risk of irreparable damage to gearbox components.
Never touch the contacts in the gearbox connector with your hands. Static discharge can seriously damage the control unit and mechatronic unit.
Touch a suitable earthed object with your hand (without gloves) to discharge any static electricity.
Pull catch upwards
arrow
and unplug electrical connector
1
for
mechatronic unit for dual clutch gearbox
J743
.
Remove nuts
2
and
3
and detach bracket for electrical wiring from gearbox.
Remove bolt and nut
2
and push bracket to one side.
Note
Item 1
can be disregarded.
Remove oil drain plug from gearbox.
Allow oil to drain off, then retighten oil drain plug.
Remove cap from breather opening and seal off with a plug from
engine bung set
VAS 6122
to prevent oil from escaping.
Carefully pull
gearbox input speed sender 3
G641
out of gearbox.
Note
The following step is necessary in order to lift the two engaging levers of the dual clutch away from the plungers of the mechatronic unit. Otherwise, the levers will jam the mechatronic unit at the plungers and prevent it from being removed.
Insert
assembly lever
T10407
below plungers
2
between gearbox housing and the two engaging levers
1
arrow
, as shown in illustration.
Only slide in
assembly lever
T10407
until groove on assembly lever is in line with rib on housing
arrows
, as shown in illustration. Do not slide it in all the way.
Note
The back of the assembly lever must make contact with the gearbox housing.
Now rotate
assembly lever
T10407
90° anti-clockwise about its own axis
arrow A
so as to lift engaging levers away from plungers
1
arrow B
.
If necessary, press the
assembly lever
T10407
against the gearbox housing with a screwdriver to prevent it from slipping out when it is turned.
Note
The
assembly lever
T10407
remains inserted between the engaging levers and the gearbox housing while removing and installing the mechatronic unit.
If necessary, press the
assembly lever
T10407
against the gearbox housing.
Caution
Risk of irreparable damage to gearbox components.
Before touching or removing the
mechatronic unit for dual clutch gearbox
J743
, always discharge any static electricity by touching an earthed object with your hand.
Never touch the contacts in the gearbox connector with your hands. Static discharge could cause irreparable damage to the control unit and, consequently, the mechatronic unit.
Touch vehicle earth with your hand (without gloves) to discharge any static electricity.
Note
Make sure that the screwdriver used to support the assembly lever
T10407
does not jam against the mechatronic unit.
Caution
Risk of damage to
mechatronic unit for dual clutch gearbox
J743
!
Do not loosen bolts securing cover on
mechatronic unit for dual clutch gearbox
J743
.
Make sure that no oil escapes through the breather hole when placing down
mechatronic unit for dual clutch gearbox
J743
after removal.
Oil that has escaped cannot be refilled!
Note
The mechatronic unit is returned for reconditioning complete with oil filling.
Remove bolts
B
in diagonal sequence.
Remove bolts
A
.
Detach mechatronic unit from gearbox.
Caution
Risk of damage to
mechatronic unit for dual clutch gearbox
J743
.
In some cases it may not be possible to remove the mechatronic unit.
This can happen if the gear actuator at the top left of the mechatronic unit is stuck.
Do not attempt to remove the mechatronic unit by force.
The mechatronic unit must be first brought into the correct position for removal by hand
Chapter
.
Installing
Tightening torques
Fig.
“
Mechatronic unit for dual clutch gearbox
J743
: tightening torque and sequence”
Note
A new mechatronic unit is supplied with the correct oil filling.
Seal off breather opening of mechatronic unit with a cap from
engine bung set
VAS 6122
to prevent oil from escaping.
Note
Make sure that all selector forks are in
“centre position”
before installing
mechatronic unit for dual clutch gearbox
J743
.
“Centre position”
is position
N
(neutral) in the illustration below.
No gear is engaged in this position, the gearbox is in neutral.
First check each of the 4 selector forks by hand.
Each selector fork has 3 positions:
Gear engaged
Neutral
N
Gear engaged
Move the 4 selector forks once into each position
arrows
, one after the other.
Then shift all selector forks back into
»centre position«
, position
N
.
Note
Turn one of the wheels slightly to make it easier to move the selector forks.
N
Neutral
R
Reverse gear
1
First gear
2
Second gear
3
Third gear
4
Fourth gear
5
Fifth gear
6
Sixth gear
7
Seventh gear
Clean sealing surface on which mechatronic unit is to be installed.
Screw in bolt
guide pins
T10406
hand-tight.
Adjusting gear actuators:
Caution
Risk of damage to
mechatronic unit for dual clutch gearbox
J743
.
Do not apply any pressure to the sensors when levering out the plungers.
Adjust the four gear actuators on the reverse side of
mechatronic unit for dual clutch gearbox
J743
to the specified positions.
Specified position:
a
= 25 mm
Clean sealing surface on mechatronic unit.
The gasket positioned round the
mechatronic unit for dual clutch gearbox
J743
must be properly seated in the groove all round.
Put on mechatronic unit.
Tighten bolts for mechatronic unit
Fig.
.
Caution
The clutches can be damaged.
If the clutch engaging levers contact the clutch actuators of the mechatronic unit abruptly, this can move the actuators out of position and activate the clutch self-adjustment. The status prior to self-adjustment cannot be recovered.
Both clutch actuators must be properly engaged in the retainers on the clutch engaging levers.
The rubber grommets of the clutch actuators must not be damaged.
The rubber grommets must seal off at the mechatronic unit properly.
Turn
assembly lever
T10407
slowly and carefully in clockwise direction and remove.
The plungers should slide slowly into the retainers.
Pull out plungers by hand until they are seated correctly in retainers.
Remove sealing plug from breather opening of mechatronic unit and fit breather cap
arrow
.
Note
If the mechatronic unit is being renewed, fit the sealing plug on the old mechatronic unit so it remains oil-tight when it is returned for reconditioning.
Do not drain oil out of the old mechatronic unit.
Remaining assembly is carried out in reverse sequence; note the following:
Fill up gear oil
Chapter
.
Fill up with coolant
Rep. gr.
19
Cooling system/coolant; Draining and filling cooling system
.
Check adjustment of selector lever cable and adjust if necessary
Chapter
.
After installing the gearbox, run the
Basic setting complete
function in
Guided Functions
Vehicle diagnostic tester
.