Part 3
WM 1001Z2 Assembling V8 4.8-litre DFI engine as of October 2008
Spray direction from side
16. Insert crankshaft and oil crankshaft bearing pin and connecting-rod bearing pin.
17. 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
18. Fit crankshaft holding bridge holding bridge 9677/1 in the centre of the crankshaft.
Crankshaft secured
19. Turn upper part of crankcase and oil cylinder liners.
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"
20. Tension piston using a commercially available piston ring restraining strap (e.g. Universal piston ring restraining strap Nr.55 ) or assembly funnel funnel 9784/1 and press piston into cylinder. When doing so, make sure that the direction of travel arrow on the piston crown is pointing in the direction of travel and the connecting rod code has been fitted facing the exhaust side. Push the pistons in until the connecting rod bearing is lying on the con-rod journal of the crankshaft. Once all the pistons with connecting rod have been pushed in, fit connecting rod cap evenly and synchronously with the correct bearing shell. Fit with new connecting rod bolt to the prescribed tightening torque. For details, see -> 131020 Removing and installing pistons on 4.8-litre DFI engines 131020 Removing and installing pistons on 4.8-litre DFI engines
Piston, connecting rod
Tensioning pistons
Piston assembly
Pressing in pistons
21. Remove crankshaft holding bridge. Apply Doboseal 224N sealant (999.915.573.43, status 09/08) 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.
Sealant application
22. Tighten M11 and M10 bearing screws to the prescribed torques. -5 and 6-
Tightening sequence for thrust-bearing screws
Lower part of crankcase
23. Fit cross bolt connection.
Tightening sequence for securing lower part of crankcase to upper part of crankcase (cross bolt connection)
24. Fit M8 screws on the side -8 and 9-. Remove emerging sealant.
25. Punch in or imprint the engine number if necessary (when replacing engine).
26. Move oil plate with all the seals into installation position and secure to the lower part of the crankcase. => Tightening torque: 10 Nm (7.5 ftlb.)
Oil guide (oil plate)
27. Grease sealing ring between the oil plate transfer pipe and oil pump sparingly with Kluber Syntheso GLEP 1 and fit oil pump. Secure the oil pump.
Oil pump on naturally aspirated engine M48/01
28. 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. 1st turn => Initial tightening: 20 Nm (15 ftlb.) ; final tightening (torque angle) => Torque angle: 90°
Oil pump chain
Countering oil pump pinion
29. Fit cover plate for oil pump drive using three screws. => Tightening torque: 10 Nm (7.5 ftlb.)
30. 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.
31. 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. see illustration, item 8
Camshafts, cylinder bank 1 to 4
32. Position cylinder heads, insert cylinder head screws and fit them. Observe tightening sequence and prescribed tightening torque.
Cylinder head 1 to 4
Tightening sequence for cylinder head
33. Fit front M8 screw of cylinder head 1 to 4. => Tightening torque: 23 Nm (17 ftlb.)
34. Make sure that the intake openings have been protected using adhesive tape or something similar to prevent them from becoming dirty.
35. Insert front camshaft mounting saddles (lower parts) of cylinder heads. Item 8