Hydraulic Control Unit
Hydraulic Control Unit
• Observe general repair notes, refer to => [ Repair Information ] Repair Information.
• Follow all safety precautions. Refer to => [ Safety Precautions and Test Procedures ] Safety Precautions and Test Procedures.
Removing
• Turn off the ignition.
- Place the vehicle on a hoist.
- Slightly lower the rear section of the exhaust system and secure it, or if necessary, remove it.
• A second technician will be needed to help remove the rear section of the exhaust system.
- Remove the bolts - arrows - and remove the wiring harness bracket - 1 - from the rear final drive.
• Mark the connectors - 2 - for the oil pressure/temperature sensor and on the clutch valves.
- Mark the connectors - 2 - on the oil pressure/temperature sensors and on the clutch valves.
- Disconnect the connector - 4 - from the all wheel drive (AWD) pump (V415).
- Unclip the wiring harness - 3 - from the final drive and the subframe - 5 through 7 - and tie it up.
- Place the drip tray under the rear final drive.
- Drain the ATF. Refer to => [ ATF in Rear Final Drive 0BF and 0BE, Draining ] ATF In Rear Final Drive 0BF and 0BE, Draining.
- Drain the gear oil. Refer to => [ Gear Oil in Rear Final Drive 0BF and 0BE, Draining ] Gear Oil In Rear Final Drive 0BF and 0BE, Draining.
- Remove the AWD pump. Refer to => [ Pump ] Pump.
• Remove the AWD pump in order to loosen and tighten the nut for the right pipe on the hydraulic control unit.
- Loosen the left - 6 - and right - 7 - pipes on the hydraulic control unit - 1 - one turn - arrows A - and then remove them from the chambers - arrows B -.
- Remove the bolts - 2 through 5 - and remove the hydraulic control unit - 1 - with the seal.
Installing
• Always follow the safety precautions when replacing the hydraulic control unit. Install the "old" sensors again if possible. Refer to => [ Safety Precautions and Test Procedures ] Safety Precautions and Test Procedures.
Conditions:
• Replace the seal between the hydraulic control unit - 1 - and the final drive housing.
• The centering pins - 18 - => [ (Item 18) Hydraulic Control Unit Housing ] Service and Repair must be installed inside the hydraulic control unit.
• The left - 6 - and right - 7 - pipes must installed loosely inside the control unit when attaching the hydraulic control unit - 1 - to the rear final drive.
Attach the hydraulic control unit - 1 - to the rear final drive as follows:
First install the pipes - 6 and 7 - into the chambers hand-tight - arrows B -.
Install the bolts - 2 through 5 - hand-tight. The bolt - 2 - has permanent seal on the bolt head. Coat the thread on this bolt with sealing compound (D 176 501 A1).
Then tighten the bolts - 2 through 5 - to the tightening specification in the following sequence: - 4 -, - 2 -, - 5 - and - 3 - (M8 x 30 mm).
Tighten the nuts - arrows A - and - arrows B - on the left - 6 - and right - 7 - pipes to the tightening specification.
- Install the AWD pump. Refer to => [ Pump ] Pump.
- Install the wiring harness - 3 - on the final drive and subframe - 5 through 7 -.
- Connect the connectors - 4 and 2 - using the markings made earlier when oil pressure/temperature sensor and the clutch valve were removed.
- If equipped, hold the wiring harness bracket - 1 - on the rear final drive and then tighten the bolts - arrows - to the tightening specification. Be careful not to pinch the wiring harness - 3 -.
• Connector allocation for the oil pressure/temperature sensor and the clutch valves :
• - 1 - = oil pressure/temperature sensor 2 (G640) connector
• - 2 - = oil pressure/temperature sensor (G437) connector
• - 3 - = AWD clutch valve 2 (N446) connector
• - 4 - = AWD clutch valve (N445) connector
- Fill the gear oil in the rear final drive and check the level. Refer to => [ Gear Oil Level in Rear Final Drive 0BF and 0BE, Checking ] Gear Oil Level In Rear Final Drive 0BF and 0BE, Checking.
- Fill the ATF in the rear final drive and check the level. Refer to => [ ATF Level in Rear Final Drive 0BF and 0BE, Checking ] ATF Level In Rear Final Drive 0BF and 0BE, Checking.
- Install and adjust rear section of exhaust system free of stress.