Part 1

WM 1001Z2 Assembling engine

Tools

Preliminary work

Check that the following assembly preconditions have been met:
- Oil guide housing pre-fitted with oil filter and oil/water heat exchanger.
- Examine the oil mist separator to check that seals and screw elements are pre-fitted.
- Check cylinder head cover (valve cover) to ensure that surrounding seal, seals for spark plug recesses, seal for hydraulic valve of camshaft control, hall sender for camshaft and oil filler cover are fitted.
- Intake-air distributor with seals, heat socket, screws and throttle housing inserted.
- Generator with both fitted coolant connection pieces and sheetmetal cable holders.
- Upper part of crankcase fitted on flywheel side with two water plugs. Screw plugs fitted.
- The upper part of the crankcase together with the engine support engine support 9676/1 is attached to the assembly support. Use the four screws mounting elements 9590 and tighten them. -> 1001IN Securing engine on assembly support (mounting bracket) 1001IN Securing engine on assembly support (mounting bracket)

Assembling engine

CAUTION

Ingress of dirt

- Danger of material damage due to blocked oil bores/oil ducts.

-> Absolute cleanliness is essential when working on the engine.
-> Lay removed engine parts on a clean base and make sure to cover them.
-> Use the cover for dust protection when fitting the engine NR.165 on the engine assembly support.

CAUTION

Heavy components

- Risk of squashing

-> Wear personal protective gear.
-> Get someone to help if necessary.

CAUTION

Leaks due to components being at too low a temperature or at different temperatures!

- If components that are cold or at different temperatures are sealed together by the application of sealant, adhesion problems and leaks can arise due to the build-up of condensation water or component distortion.

-> Components must have reached at least 17°C throughout.
-> Components must not be too hot (distortion).
-> Spare parts that are stored in the cold or heat (strong sunlight), must be brought to room temperature or the same temperature as other parts before installation.

CAUTION

Emerging residual fluid can soil the engine!

- Residual fluid (fuel, oil, Pentosin, coolant, etc.) will emerge even after a long time when disassembling and assembling the engine.

-> Place a drip tray under the engine at the assembly support.
-> Have a sufficient number of cleaning cloths ready.
-> Close off engine openings with plugs.

Information

The tightening specifications for the basic engine are stored centrally. -> 1001IN Tightening torques, tightening sequences, assembly overviews [1][2]Specifications. Tightening torques and assembly instructions for other assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.

Information

- The bearing shells are available in various classes. The classes are indicated by the colour marking on the outside. For every bearing (main and connecting rod bearings), the colour marking must match the corresponding letter on the flywheel flange of the crankshaft. -arrow- Each letter on the flywheel flange of the crankshaft indicates the correct colour classification of the bearing shell.

Colour marking on bearing shell

Information

- The corresponding connecting-rod bearing shells must be selected according to the marking on the crankshaft transmission flange (4-digit) and inserted into the connecting rod.

- When removing the pistons with connecting rods, the pistons should be marked with a water-resistant marker on both the piston and connecting rod according to cylinder and cylinder bank.

- The removed pistons and connecting rods must be cleaned carefully so as not to remove the markings.

- The connecting rod code is installed to the exhaust side as standard. The direction of travel arrow on the DFI piston is always on the same side as the connecting rod code -A-. The pistons are assigned to the cylinder bank (1 to 4 and 5 to 8), i.e. because of the DFI combustion chamber recess there are two different pistons for the left and right cylinder bank.

- When installing the piston in the crankcase, the direction of travel arrow must point in the direction of travel when installed. It is always on the same side as the connecting rod code. The combustion chamber recess on the piston is always on the intake side. Note the assignment of the pistons to the cylinder bank.

- Naturally aspirated engines and turbo engines have different pistons.

Connecting rod code and direction of travel arrow

- The code on the connecting-rod big end and connecting rod cap must always be on the same side and at the exhaust side. -A- Note: Select the correct piston for the correct cylinder bank. Install with connecting rod code on the exhaust side with the direction of travel arrow on the piston.

Connecting rod code "A"

Information

- Connecting rod bolts must always be replaced.

Information

Please observe the following for the V6 =>

- The repair concepts for the V6 are the same as for the V8.

- The special features and component deviations are listed and shown in -> 1001IN Tightening torques, tightening sequences and assembly overviews [1][2]Specifications.

- More significant deviations are shown in separate descriptions.

- If no special features are specifically highlighted, the assembly and adjustment instructions for the V8 apply.

Information

- Particular care and attention must be paid to the combined V6 oil pump balance shaft module during disassembly and assembly work. This is completely different from the V8 oil pump concept.

- The V6 oil pump balance shaft module with the balance weight is installed at a defined position with respect to the crankshaft.

- The balance shaft in the V6 oil pump balance shaft module is fixed to the crankshaft. Non-observance of this requirement results in strong vibrations in the engine.

- For details, see -> 172019 Removing and installing oil pump Removal and Replacement.

1. Place crankshaft bearing shells into the lower part of the crankcase.
1.1. Select crankshaft bearing shell classification based on the inscription on the crankshaft's flywheel flange -9-. Example: YYYYB YYYY mean 5 main shaft bearings and 4 double connecting rod bearings (8 connecting rods in total). The letters are the abbreviations for the colour code of the bearing shells (Y for yellow, B for blue, R for red, N for green). Based on the example above, yellow bearing shells are to be selected for the main shaft bearings 1 to 4 and a blue bearing shell is to be selected for the fifth main shaft bearing. The connecting rod bearing shells should all have a yellow marking in this case.

Crankshaft

1.2. Place crankshaft bearing shells with lubricating groove and bore -2- into the upper part of the crankcase -1-. Smooth crankshaft bearing shells -3- belong in the lower part of the crankcase. Insert the thrust washers into the centre with grooves facing outwards (affix using multipurpose grease) or alternatively wait until after the crankshaft has been inserted.

Inserting bearing shells

Thrust washer

1.3. Oil crankshaft bearing shells on the outside and inside with engine oil and insert correctly into the lower part of the crankcase according to the twist lock. Place lower part of crankcase on a clean surface. The retaining lugs (twist lock) prevent it from being installed incorrectly. As the thrust washers fall off without the crankshaft, do not insert until after the crankshaft is fitted.
2. If you have not already done so, fit knock sensors on the upper part of the crankcase using screws.
2.1. Align the knock sensors between cylinder 1 and 2 and cylinder 5 and 6 parallel to the cylinder head and the plug connection parallel to the starter. Fit knock sensors hand-tight.
2.2. Insert starter briefly and align concealed knock sensors so that there is no knock sensor near the starter. Remove the starter. Fit plug connection for knock sensor between cylinders 3 and 4 in the direction of the water pump so that it is turned upwards and slightly towards the cylinder head. Fit plug connection for knock sensor between cylinders 7 and 8 in the direction of the flywheel so that it is turned upwards and slightly towards the cylinder head.
2.3. Fit knock sensors correctly.

Knock sensors

2.4. Insert two seals for the thermostat housing into the upper part of the crankcase on both sides. -2-

Seals between crankcase and thermostat housing

3. Check coolant guide (collection pipe) to make sure that the sealing faces are clean and free of burrs. Fit metal seals at the left and right, screw in screws securely on metal seals by hand. Move coolant guide at the upper part of the crankcase into installation position and fit it.

Coolant guide

4. Fit oil spray jets -6-.

Upper part of crankcase

Insert oil spray jets into the upper part of the crankcase and screw them on. To do this, grease the sealing ring sparingly with Kluber Syntheso GLEP 1 and fit it. Check that oil spray jets are pointing in the correct direction of spray toward the inside of the piston crown. The oil spray jet must be aimed at the piston crown. => Spray direction => Spray direction from side

Spray direction

Spray direction from side

5. Pre-fit spring wedge of crankshaft into the corresponding groove on the crankshaft using a plastic hammer if necessary.
6. Pre-fit all pistons with connecting rods and piston rings, number by cylinder and place to one side. For details, see -> 131037 Disassembling and assembling pistons 131037 Disassembling and assembling pistons

Piston, connecting rod

7. Check that all the seals are installed in the oil plate (oil return). => Oil return (oil plate), 4WD shown

Oil return (oil plate), 4WD shown

8. If you have not already done so, drive dowel sleeves for the metal seals in the timing-case cover using a copper or plastic hammer.
9. Insert new metal seals on the timing-case cover and press onto dowel sleeves.
10. Oil pump is pre-fitted with the oil pressure control valve.
11. Cylinder heads fitted with solenoid valves of the valve lift switchover, camshaft housings loosely positioned and removed camshafts prepared. Alternatively, the camshaft housings, which have been marked according to installation position, can be set down on a clean surface together with the corresponding camshafts. Cam followers and injectors are fitted.
12. If you have not already done so, drive in dowel sleeves on auxiliary unit bracket for power-steering pump or tandem pump using a copper or plastic hammer.
13. Move starter into installation position and screw down. -> 276019 Removing and installing starter 276019 Removing and Installing Starter
14. Insert crankshaft and oil crankshaft bearing pin and connecting-rod bearing pin.
15. First position timing chain pinion with the ring gear of the oil pump drive onto the crankshaft stub (check that the two diamond washers at the front and rear on the ring gear are clipped in -1- ). Then position the drive pinion of the oil pump chain -2- with respect to the crankcase.

Timing chain pinion on crankshaft stub

Timing chain pinion with two diamond washers

16. Fit crankshaft holding bridge holding bridge 9677/1 in the centre of the crankshaft.

Crankshaft secured

17. Turn upper part of crankcase and oil cylinder liners.
18. Pre-tension pistons using an assembly funnel funnel 9784/1 and press pistons into the cylinder. For details, see -> 131020 Removing and installing pistons 131020 Removing and installing pistons
19. Remove crankshaft holding bridge. Apply Doboseal 224N sealant (999.915.573.43, status 09/09) to the lower part of the crankcase as shown. Insert sealing ring -3- into the upper part of the crankcase and position the lower part of the crankcase onto the upper part of the crankcase. Insert all the fastening screws, fit to the prescribed tightening torque within 5 minutes and wipe off excess sealant.

Applying sealant

20. Tighten M11 and M10 bearing screws to the prescribed torques. -5 and 6-. The bearing screws for the 4WD shaft are shorter. Do not use the wrong screws.

Tightening sequence for thrust-bearing screws

Lower part of crankcase, 2WD

Lower part of crankcase, V8 4WD

21. Fit cross bolt connection.

Tightening sequence for securing lower part of crankcase to upper part of crankcase (cross bolt connection)

22. Fit M8 screws on the side -8 and 9-. Remove emerging sealant.
23. Punch in or imprint the engine number if necessary (when replacing engine). Use a 4-mm number embossing tool and counter at the cast-metal part with a hammer.
24. Move oil plate with all the seals into installation position and secure to the lower part of the crankcase.

Oil return (oil plate), 2WD

Oil return (oil plate), 4WD

25. Fit the oil pump => Oil pump on naturally aspirated engine. Fit suction tube for auxiliary sump => Suction tube for auxiliary sump.

Oil pump on naturally aspirated engine

Suction tube for auxiliary sump

26. Fit oil pump sprocket with drive chain with respect to the crankshaft chain pinion => Oil pump chain. Counter the oil pump sprocket at the oil pump using a screwdriver and fit a new screw.

Oil pump chain

Countering oil pump pinion

27. Fit cover plate for oil pump drive (drive pinion cover) using three screws.
28. Turn engine and clean sealing faces. Blow out bores of cylinder head screws. Position both cylinder head seals. Part number/marking facing upward. When doing so, make sure that the cylinder head gasket is positioned on the dowel sleeves.
29. Unscrew front camshaft mounting saddles (lower parts) of the cylinder heads (if you have not already done so), as the bores in the cylinder head screws are covered. -8-

Camshafts (cylinder bank 1 to 4 shown)

30. Position cylinder heads, insert cylinder head screws and fit them. Observe tightening sequence and prescribed tightening torque.

Cylinder head (1 to 4 shown)