Removing and Installing Oil Guide Housing

Removing and installing oil guide housing

Preliminary work

1. Remove vibration balancer.
2. Remove front-axle carrier.
3. On 4WD vehicles, remove all-wheel final drive completely (including transverse shaft and engine carrier)

Removing oil guide housing

Information
* The description only applies when installed.
* If the oil guide housing is removed when the transmission is disconnected, the oil guide housing must be aligned with the aid of a dial gauge.
* To remove the oil guide housing, it is not necessary to remove the timing case cover. If the timing case cover is removed while carrying out work later, the oil guide housing must also be removed.

Oil/water heat exchanger, oil filter for 4WD

1 - Oil guide housing
2 - Oil filter cover
3 - Oil filter
4 - Oil-filter sealing ring
5 - Oil duct adapter (cannot be replaced)
6 - Heat exchanger seal
7 - Oil-water heat exchanger
8 - Screw, M6 x 20; self-tapping screws ex-works; metric screws can also be used

Lower part of crankcase V8 4WD

1 - Lower part of crankcase
2 - Straight pin, 6 x 18
3 - Dowel sleeve
4 - Seal
5 - Sealing flange
6 - Screw, M6 x 20
7 - Screw, M8 x 35
8 - Screw, M8 x 50
9 - Sealing rings for sealing flange/cross tube
10 - Cross tube for all-wheel drive cross shaft
11 - Aluminum screw, M8 x 70; (cross bolt connection); always use new aluminum screws; and
12 - Thrust-bearing screw M10; tighten screws within 5 minutes; observe tightening sequence.
13 - Thrust-bearing screw M11; tighten screws within 5 minutes; observe tightening sequence.
14 - Sealing ring
- - Sealant application - Doboseal 224N (999.915.573.43, status 09/08)

Applying sealant for oil guide housing, 4WD

1 - Sealant application (geometry, sealing bead 1 mm); Doboseal 224N (999.915.573.43, status 09/08)

Oil guide housing with accessories

1 - Screw, M6 x 20
2 - Sealing flange
3 - Sealing ring
4 - Oil guide housing to lower part of crankcase - aluminum screw; always use new aluminum screws and
5 - Oil level sensor
6 - Oil level sensor to oil guide housing (steel screw);
7 - Timing-case cover to oil guide housing - aluminum screw; always use new aluminum screws and

1. Remove transverse shaft/engine carrier -1-.

Removing transverse shaft/engine carrier

1.1. Unscrew fastening screws -arrows-.
1.2. Remove transverse shaft/engine carrier -1-.
2. Remove transverse shaft cover -1- on both sides.

Transverse shaft cover

2.1. Unscrew fastening screws -arrows- on both sides.
2.2. Remove one transverse shaft cover -1-.
2.3. The second transverse shaft cover will be removed with the transverse shaft pipe -1-. It does not matter whether the transverse shaft pipe -1- is removed with the left or right cover.

Transverse shaft pipe with cover

2.4. Remove housing sealant -2- under both transverse shaft covers.
3. Unclip coolant hoses from the clip on the oil/water heat exchanger -8-.

Screws between timing-case cover and oil guide housing

5. Remove sensor for oil pressure display.
6. Unscrew fastening screw between the timing-case cover and oil guide housing underneath the oil pressure sensor.
7. Disconnect coolant supply line to the oil/water heat exchanger. To do this, clamp the coolant hoses for the oil/water heat exchanger with hose clamps. For example, use hose clamp 3093 or hose clamp 3094. Pull the coolant hoses off the oil/water heat exchanger. Coolant will run out.
8. Drain engine oil.
9. Remove the two side oil extraction lines at the turbo engine -5- and (bottom illustration) -5- from the oil guide housing.

Oil circuit for turbocharger, cylinders 1 to 4

1 - Vent line for turbocharger, cylinders 1 to 4; vent line to oil extraction line for turbocharger and holding clamp for vent line to collection pipe
2 - Oil feed line for turbocharger, cylinders 1 to 4; oil feed line for turbocharger to connection piece; oil feed line for turbocharger to cylinder head
3 - Holder
4 - Seal
5 - Oil extraction line
6 - Screw, M6 x 12; oil extraction line for turbocharger to oil guide housing and oil feed line for turbocharger at the holder
7 - Screw, M6 x 16

Oil circuit for turbocharger, cylinders 5 to 8

1 - Oil feed line for turbocharger, cylinders 5 to 8; oil feed line for turbocharger to connection piece; oil feed line for turbocharger to cylinder head
2 - Vent line for turbocharger, cylinders 5 to 8; vent line to oil extraction line for turbocharger
3 - M6 screw; oil extraction line for turbocharger to oil guide housing and holding clamp
4 - Holding clamp
5 - Oil extraction line
6 - Screw, M6 x 16
7 - Seal

10. Remove oil level sensor. To do this, pull off the connector and release the cable.

Oil level sensor

11. Remove screws -arrows-. Remove oil level sensor by turning it. Oil will start to drip.

Screws on oil level sensor

12. Remove oil pressure control valve.
13. Remove oil pan.
14. Remove the bottom two screws between the transmission and oil guide housing.

Screws between oil guide housing and transmission

15. After removing the oil guide housing, the connecting tubes (oil lines and oil pipes) between the oil pump and oil guide housing must be removed.

Do not forget the side oil suction pipes on the turbo engine. See illustrations.

Oil lines on turbo engine

1 - Suction pipe between the oil pump and turbocharger (fitted in oil guide housing)
2 - Suction pipe between the oil pump and turbocharger (fitted in oil guide housing)
3 - Intake pipe on oil pump
4 - Sealing ring
5 - Oil pressure pipe
6 - Sealing ring
7 - Sealing ring; oil before fitting
8 - Oil regulating line
9 - Sealing ring
10 - Sealing ring; oil before fitting
11 - Oil pipes to oil pump and oil guide housing
12 - Oil pipes to oil pump and oil guide housing

Oil lines on turbo engine, view with oil pan removed

1 - Mounting point for oil pressure pipe
2 - Mounting point for oil extraction line for turbocharger, cylinders 5 to 8
3 - Mounting point for oil extraction line for turbocharger, cylinders 1 to 4
4 - Mounting point for auxiliary sump intake manifold
5 - Mounting point for oil pump intake manifold
6 - Mounting point for oil regulating line

Oil lines on naturally aspirated engine

1 - Oil pump intake manifold; screw M6 x 20
2 - Sealing ring
3 - Oil pressure pipe; screw M6 x 16
4 - Sealing ring
5 - Sealing ring; oil before fitting
6 - Oil regulating line; screw M6 x 16
7 - Sealing ring
8 - Sealing ring; oil before fitting
9 - Oil pipes to oil pump and oil guide housing
10 - Oil pipes to oil pump and oil guide housing

Oil lines on naturally aspirated engine, view with oil pan removed

1 - Mounting point for oil pressure pipe
2 - Mounting point for auxiliary sump intake manifold
3 - Mounting point for oil pump intake manifold
4 - Mounting point for oil regulating line

16. Loosen oil guide housing. To do this, unscrew the screws -7- and -4- on the lower part of the crankcase.

Oil guide housing with accessories (example for 2WD)

1 - Screw, M6 x 20
2 - Joint flange
3 - Sealing ring
4 - Oil guide housing to lower part of crankcase - aluminum screw; always use new aluminum screws!
5 - Oil level sensor
6 - Oil level sensor to oil guide housing (steel screw)
7 - Timing-case cover to oil guide housing - aluminum screw; always use new aluminum screws!

17. Remove bonding (sealant) between the oil guide housing and crankcase.

Carefully pry off the cast lugs using a screwdriver or a soft rubber hammer if necessary.

18. Guide the oil guide housing carefully around the oil pump and remove it.
19. Remove sealing ring for the lower part of the crankcase.
20. Clean sealing faces. Brush off remaining sealant with a plastic brush and then degrease the sealing face.

Installing oil guide housing

Information
If cold or excessively low-tempered components are sealed to each other by applying sealant, leaks can occur because of condensed water forming or components distorting. Components must be uniformly at least -> Temperature: 17 degrees C.

Information
When installing the oil guide housing, make sure that it is perfectly aligned and that there is no dirt or dust between the components. Fit the oil guide housing straight. The maximum offset must be less than 0.1 mm and it must not project over the crankcase. Otherwise, leaks can occur while driving.

Information
The tightening specifications for the basic engine are stored centrally. Tightening torques and assembly instructions for other affected assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.

1. Clean sealing surfaces on the oil guide housing and crankcase. The sealing surfaces must be dry and free of grease.
2. Apply liquid sealant to the oil guide housing.

Apply the sealant with the hand-held cartridge.

The contour of the sealing bead must match the figure shown below.

The sealing bead should be approx. 1.0 mm wide and high.

Ensure that the bead of sealant is continuous and that there are no gaps.

Applying sealant to oil guide housing (2WD)

1 - Sealant application (geometry, 1-mm bead of sealant)
2 - Sealant application - Doboseal 224N (999.915.573.43, status 09/08)
A - Direction of travel

Applying sealant to oil guide housing (4WD)

1 - Sealant application (geometry, sealing bead = 1 mm); Doboseal 224N (999.915.573.43, status 09/08)

3. Insert a new sealing ring into the ring groove on the lower part of the crankcase and bond it with a very small amount of grease.

Information
* If the transmission or engine is removed, the oil guide housing must be aligned using a dial gauge.

4. Place the oil guide housing on the crankcase and press evenly against the transmission bell housing.
5. Screw in a fastening screw on each corner of the oil guide housing and tighten screws by hand.
6. Then screw in all screws by hand. While doing this, push the oil guide housing towards the transmission. Also fit the two transmission screws and tighten hand-tight.
7. Beginning at the transmission flange and proceeding forwards, tighten the screws evenly and crosswise.

Do not forget the screws from the top to the timing-case cover.

Screws between timing-case cover and oil guide housing

Screws between oil guide housing and transmission

9. After fitting the oil guide housing, the connecting tubes (oil lines and oil pipes) between the oil pump and oil guide housing must be fitted.

Fit the side oil suction pipes -1- and -2-.

Oil lines on naturally aspirated engine, view with oil pan removed

1 - Mounting point for oil pressure pipe
2 - Mounting point for auxiliary sump intake manifold
3 - Mount for oil pump intake manifold
4 - Mount for oil regulating line

10. Fit the oil pressure control valve.
11. Fit oil pan.
12. Insert and fit the oil level sensor by turning it. Plug in connector and lay the cable. Fit screws -arrows-.

Oil level sensor

Screws on oil level sensor

13. Fit the two side oil extraction lines at the turbo engine -5- and (bottom illustration) -5- from the oil guide housing.

Oil circuit for turbocharger, cylinders 5 to 8

1 - Oil feed line for turbocharger, cylinders 5 to 8; oil feed line for turbocharger to connection piece; oil feed line for turbocharger to cylinder head
2 - Vent line for turbocharger, cylinders 5 to 8; vent line to oil extraction line for turbocharger
3 - M6 screw; oil extraction line for turbocharger to oil guide housing and holding clamp
4 - Holding clamp
5 - Oil extraction line
6 - Screw, M6 x 16
7 - Seal

14. Install one transverse shaft cover with the transverse shaft pipe -1-. Replace sealing rings in the covers.

Transverse shaft pipe with cover

14.1. Apply housing seal -2- to the seating points of the two transverse shaft covers close to the edge of the housing.
14.2. Position transverse shaft cover with transverse shaft pipe -1-.

Make sure that the transverse shaft pipe is protruding at a center position from the opposite opening on the oil guide housing.

The -TOP- marking must be facing upwards.

14.3. Screw in fastening screws -arrows-.
15. Install the second transverse shaft cover -1-.

Transverse shaft cover

15.1. Position the transverse shaft cover -1-. Make sure that the transverse shaft pipe is inserted into the center opening on the cover. The -TOP- marking must be facing upwards.
15.2. Screw in fastening screws.
16. Install transverse shaft/engine carrier -1-.

Installing transverse shaft/engine carrier

16.1. Position transverse shaft/engine carrier -1- on the left side of the oil guide housing.
16.2. Screw in fastening screws -arrows-.

Fitting oil guide housing using a dial gauge

Information
When installing the oil guide housing, make sure that it is perfectly aligned and that there is no dirt or dust between the components. Fit the oil guide housing straight. The maximum offset must be less than 0.1 mm and it must not project over the crankcase. Otherwise, leaks can occur while driving.

Information
* The following work steps are only necessary if the transmission is disconnected at the time the oil guide housing is being installed.

Place the oil guide housing on the crankcase and fit a fastening screw on each corner.

1. Insert the dial gauge into the universal dial gauge bracket and position it so that the dial gauge has a preload of about 1 mm.

Dial gauge

2. Set dial gauge scale to 0. To do this, place the dial gauge bracket on a completely flat surface (e.g. crankcase flange) and turn the dial gauge scale until the pointer is at 0.

Dial gauge and dial gauge bracket

3. Measure the offset. In order to do this, push with the bracket starting from the crankcase flange towards the oil guide housing flange (the foot of the dial gauge bracket is located on the other component like the dial gauge probe) and measure the offset. The oil guide housing must not be set back any more than 0.1 mm. Even the slightest projection must be corrected.

Measuring offset

4. Align the oil guide housing by tapping lightly with a rubber hammer.
5. Once the oil guide housing is aligned, tighten the four fastening screws. Then check the position of the oil guide housing again with the dial gauge.

Checking position of oil guide housing again

6. Tighten the remaining fastening screws. For details of tightening torques, see Installation.

Subsequent work

1. Fit all-wheel final drive.
2. Install front-axle carrier.
3. Fit vibration balancer.
4. Clip in coolant hoses on the oil/water heat exchanger -8-.

Coolant return on turbo engine

1 - Connection piece on generator
2 - Connection piece screw
3 - Screw, M6 x 20
4 - Coolant return line
5 - Coolant return hose assembly
6 - Holder
7 - M6 screw - aluminum screw; always use new aluminum screws and
8 - Clip

5. Remove engine bridge.
6. Fill in engine oil.
7. Connect coolant supply line to the oil/water heat exchanger. Connect the coolant hoses to the oil/water heat exchanger at the same time. Remove hose clamps.
8. Check the engine coolant level and top up if necessary.
9. Align the front axle and bleed all open systems.
10. Carry out a check. After test-driving the vehicle, check the engine for leaks. Then check the oil level.