Hydraulic Control Unit, Removing And Installing: Installing

Fig 1: Identifying Hydraulic Control Unit Tightening Sequence

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Follow all safety precautions exactly when replacing the hydraulic control unit. Install the "old" sensors again if possible. Refer to SAFETY PRECAUTIONS AND TEST PROCEDURES

Conditions

Replace the seal between the hydraulic control unit -1- and the final drive housing.
The centering pins must be installed inside the housing for the hydraulic control unit. Refer to -item 18- Hydraulic Control Unit Housing (See Figure).
The left -6- and right -7- lines must be installed loosely when attaching the hydraulic control unit -1-.

Attach the hydraulic control unit -1- to the rear final drive as follows:

First install the lines -6 and 7- into the chambers hand-tight -arrows B-.

Then install the bolts -2 through 5- hand-tight. One bolt -2- has a permanent seal on the head. Coat the thread with Sealing Compound D 176 501 A1.

Tighten the M8 x 30 bolts -2 through 5- to the tightening specification in the sequence: -4, 2, 5 and 3-.

Tighten the nuts -A arrows- and -B arrows- on the left -6- and right -7- lines to the tightening specification.

-- Install the All Wheel Drive Pump -V415-. Refer to All Wheel Drive Pump -V415-, REMOVING AND INSTALLING .

-- Install the wiring harness -3- to the final drive and subframe -5 through 7-.

Fig 2: Identifying Rear Final Drive Wiring Harness Bracket

Courtesy of AUDI OF AMERICA, LLC

-- Connect the connectors -4 and 2-. Pay attention to the marks made during the removal, that identify the allocation to the Oil Pressure/Temperature Sensor -- and which connectors go to the All Wheel Drive Clutch Valve -N445- OR All Wheel Drive Clutch Valve 2 -N446-, REMOVING AND INSTALLING .

-- If equipped, position the wiring harness bracket -1- on the rear final drive and tighten the bolts -arrows- to the tightening specification. Make sure the wiring harness -3- does not get pinched.

NOTE:

Allocation for the Oil Pressure/Temperature Sensor -- and Clutch Valves -- connectors:

Fig 3: Identifying Oil Pressure/Temperature Sensor Connectors

Courtesy of AUDI OF AMERICA, LLC

-1- = Oil Pressure/Temperature Sensor 2 -G640- Connector

-2- = Oil Pressure/Temperature Sensor -G437- Connector

-3- = All Wheel Drive Clutch Valve 2 -N446- Connector

-4- = All Wheel Drive Clutch Valve -N445- Connector

-- Fill the rear final drive with gear oil and then check the level. Refer to GEAR OIL LEVEL IN REAR FINAL DRIVE 0BF AND 0BE, CHECKING .

-- Fill with ATF in the rear final drive and check the ATF level. Refer to ATF LEVEL IN REAR FINAL DRIVE 0BF AND 0BE, CHECKING .

-- Install the rear section of the exhaust system and align it so it is free of tension. Refer to EXHAUST PIPES/MUFFLERS for engine code CALA, EXHAUST PIPES/MUFFLERS for engine codes CCBA, CGXC, CTUB, or EXHAUST PIPES/MUFFLERS for engine codes CAED, CAEB, CPMB, CPMA .