Installing mechatronic unit for dual clutch gearbox J743 — VW

Installing
mechatronic unit for dual clutch gearbox
J743
Special tools and workshop equipment required
Guide pin
T10406
Note
A
»new«
mechatronic unit is correctly filled with oil.
The mechatronic unit is supplied with the
protective cap
0AM 325 120 A
fitted to seal it off.
After unpacking new mechatronic unit, do not discard the packaging or the cap on the breather pipe. These will be needed for returning the old mechatronic unit.
Installing
All selector forks must be
»in neutral position«
before installation of mechatronic unit.
Note
Make sure that all selector forks are located in
N
,
»in the middle«
, and therefore that the gearbox is in neutral.
Therefore, check each of 4 selector forks by hand.
Every selector fork has 3 positions:
»gear selected - neutral - gear selected«
.
Also, move each fork into each position in succession. Then disengage all gears and return selector forks to middle position
»neutral«
.
Note
»Neutral, neutral, neutral«
, or gearbox will not function!
You can turn the front gear slightly for assistance. This makes it
»easier«
to shift the forks.
Please clean sealing surface where mechatronic unit will make contact later on.
Oil residues on sealing surface will later result in a misdiagnosis of
»leaking«
.
Screw in
guide pin
T10406
hand-tight.
Make sure that all 4 gear actuators project 25 millimetres
a
.
Caution
Handle with care. When levering the plungers out of the mechatronic unit, make sure that you do not brace yourself on the sensors.
Please clean sealing surface of mechatronic unit.
Watch out for seal on mechatronic unit.
Seal must be pushed in all around.
Look at
gearbox input speed sender 3
G641
. Clip must not be damaged.
The
assembly lever
T10407
is inserted between engaging lever and gearbox housing.
Dowel sleeves
1
and
2
for centring mechatronic unit on gearbox housing must both be installed.
Put on mechatronic unit.
When gripping and putting on, make sure selector forks are not inadvertently pressed out of their position.
Also observe engaging levers and plungers on mechatronic unit.
Screw in 7 new bolts and tighten until finger-tight.
Remove
guide pins
T10406
again.
Make sure that plungers meet up correctly in cups of engaging levers.
Pull out plungers by hand until they are seated in cups.
Plungers can be moved into position with a hook bent from a piece of welding wire (local manufacture).
Now check seat of plungers again.
Plungers that are not seated correctly will damage mechatronic unit.
Tighten mechatronic unit diagonally to 10 Nm.
Turn
assembly lever
T10407
clockwise and remove it.
Install
gearbox input speed sender 3
G641
.
Look at sender. Clip must not be damaged.
Sender lug must be fully and firmly in contact with gearbox housing. If sender is
»loose«
or clip is broken, renew mechatronic unit.
Remove plug and put breather cap
arrow
in place.
Caution
Risk of damaging gearbox components.
Do not under any circumstances touch the contacts in the gearbox connector by hand. Static discharge could destroy the control unit and, consequently, the mechatronic unit.
To become electrostatically discharged, touch an earthed object by hand (without gloves)
Anchor
.
Fit connector of mechatronic unit and lock.
Attach all retainers and brackets to front of gearbox.
In some vehicles, a cover is fitted over the engaging levers.
The cover prevents dirt getting in.
Torque setting: 8 Nm
Now add gear oil
Chapter
.
Install starter
Electrical system
Rep. gr.
27
Starter; Removing and installing starter
.
Fit charge air or coolant hoses if these were removed.
Install battery and battery tray
Electrical system
Rep. gr.
27
Battery; Removing and installing battery
.
Install air filter housing:
Petrol engine
Rep. gr.
24
Injection system; Removing and installing air filter
.
Diesel engine
Rep. gr.
23
Diesel direct injection system; Assembly overview - air filter
.
If necessary, top up coolant
Rep. gr.
19
Parts of cooling system
.
Install noise insulation
General body repairs, exterior
Rep. gr.
50
Noise insulation; Assembly overview - noise insulation
.
Connect
Vehicle diagnostic tester
and perform
basic measurement
Chapter
.
Place plug on
»removed«
mechatronic unit if necessary.
This way, the mechatronic unit can be sent sealed in oil-tight condition.