Transmission and Drivetrain: Service and Repair
Hydraulic Control Unit
1 Bolt
• 5 Nm
2 All Wheel Drive (AWD) Pump (V415)
• Removing and installing, refer to => [ Pump ] Pump
3 O-ring
• Always replace if removed
4 Adapter
• The adapter could fall out when removing the AWD pump.
• Insert the adapter into the recesses in the hydraulic pump before installing the AWD pump.
5 Hydraulic Pump
• Consists of a guide ring, a housing and 6 pistons
• Assembling, refer to => [ Assembling the Hydraulic Pump ]
6 Ball Bearing
• Can be removed and installed by hand
7 Left Pipe
• Tighten the nuts to 30 Nm.
• Installed between the hydraulic control unit and the left chamber
• First install the nuts hand-tight
8 O-ring
• Always replace if removed
9 Oil Pressure/Temperature Sensor (G437)
• 10 Nm
• Brown connector
• Removing and installing, refer to => [ Oil Pressure/Temperature Sensor (G437) or Oil Pressure/Temperature Sensor 2 (G640) ] Oil Pressure/Temperature Sensor (G437) or Oil Pressure/Temperature Sensor 2 (G640)
10 Oil Pressure/Temperature Sensor 2 (G640)
• 10 Nm
• Black connector
• Removing and installing, refer to => [ Oil Pressure/Temperature Sensor (G437) or Oil Pressure/Temperature Sensor 2 (G640) ] Oil Pressure/Temperature Sensor (G437) or Oil Pressure/Temperature Sensor 2 (G640)
11 All Wheel Drive (AWD) Clutch Valve 2 (N446)
• Color: brown
• Removing and installing, refer to => [ Clutch Valve or Clutch Valve 2 ] Clutch Valve or Clutch Valve 2
• Installation position: The connector faces upward toward the oil pressure/temperature sensor
Do not confuse with the AWD clutch valve.
12 All Wheel Drive (AWD) Clutch Valve (N445)
• Color: black
• Removing and installing, refer to => [ Clutch Valve or Clutch Valve 2 ] Clutch Valve or Clutch Valve 2
• Installation position: The connector faces upward toward the oil pressure/temperature sensor
Do not confuse with the AWD clutch valve 2.
13 Bolt
• 2.5 Nm
14 O-ring
• Always replace if removed
• Position on the clutch valve
15 Compression Spring
• Install in the guide - item 16 - => [ (Item 16) Guide ]
16 Guide
• Installation position: The larger diameter faces the ball - item 17 - => [ (Item 17) Ball ]
17 Ball
• Insert into the guide before installing - item 16 - => [ (Item 16) Guide ]
18 Hydraulic Control Unit Housing
• With centering pins - arrows -
• The centering pins hold the hydraulic control unit and seal to the final drive housing.
19 Ball
• Insert into the hole in the shuttle valve - item 21 - => [ (Item 21) Shuttle Valve ] before installing
20 O-ring
• Always replace if removed
21 Shuttle Valve
• 8 Nm
• Removing and installing, refer to => [ Removing and Installing the Shuttle Valves ]
22 Gasket
• With a screen
• Mount on the centering pins on the hydraulic control unit housing
23 Right Pipe
• Tighten the nuts to 30 Nm.
• Installed between the hydraulic control unit and the right chamber
• First install the nuts hand-tight
Assembling the Hydraulic Pump
- Insert the 6 pistons - A - into the housing - B -.
- Position the guide ring - C - so that the piston touches the collar - arrow -.
- Install the hydraulic pump - 1 - and the guide ring - 2 - into the hydraulic control unit housing.
Functional Check
- Turn the hydraulic pump - 1 - several times. Pay attention to the following when doing this:
• The hydraulic pump must not get stuck or tilt when being turned.
• All the pistons must be pulled out and pushed in.
Removing and Installing the Shuttle Valves
• Remove the AWD pump, the hydraulic pump and the ball bearing beforehand - item 6 - => [ (Item 6) Ball Bearing ].
- Remove the shuttle valves - A -. The ball - C - must be removed as well.
- Insert the ball into the hole in the shuttle valve when installing.
- Carefully install the shuttle valve with a new O-ring - B - all the way in.
• The shuttle valve must be deeper than the housing surface - arrow -. If this does not happen, then remove the valve again and adjust the position of the ball.
- Tighten the shuttle valve to the tightening specification - item 21 - => [ (Item 21) Shuttle Valve ].