Note: The presence of metal shavings or large amounts of small metal particles found during engine rebuild may indicate damage to the crankshaft and connecting rod bearings. To prevent further damage, thoroughly clean the oil passages and replace the oil jets, oil cooler and oil filter.
1. The details of the installation of the crankshaft and connecting rod-piston group are shown in the accompanying illustrations.
42.1a Crankshaft installation details
1 Upper main bearing shell (with lubrication groove)
2 Helical gear of the crankshaft, for driving the balance shaft module and the oil pump, is replaced together with the intermediate gear
3 Lower main bearing shell (without lubrication groove)
4 Main bearing thrust washers No.3
5 Bolts, to be replaced, 65 Nm, then tighten to an angle of 90°
6 Main bearing caps, No.3 - with grooves for washers 4
7 Needle bearing, only on models with DSG
8 Crankshaft
42.1b Connecting rod and piston group parts
1 Piston rings are installed at an angle of 120° between the locks
2 Piston with combustion chamber, arrow on the bottom points towards the timing drive, numbering from the timing drive side
3 Piston pin, heat to 60°C for easier installation
4 Retaining ring
5 Connecting rod, replaceable only in pairs with cover 8, with marks indicating cylinder (A) and timing drive side (B)
6 Main bearing shells
7 Cylinder block
2. If the removed parts are to be reused, arrange them so that they will be in the same locations and orientations when reinstalled.
3. Replacing the needle bearing on models with DSG is done in the same way as on 3.6 l petrol engines (see Section 14). Install the bearing to a depth of 1.5-1.8 mm.
4. The connecting rod bearing shells installed on the connecting rod side are made of a more wear-resistant material than the lower shells and are marked with a black line on the working surface in the connection area. The upper shells can be distinguished by a black marking on the mating surface.
5. Connecting rods and connecting rod bearing caps are manufactured using a chipping method, so they should only be replaced together. The marks on the connecting rods and connecting rod bearing caps should be on the same side. Install the connecting rod bearing shells in the center (both in the connecting rod and in its cover), so that the distance on both sides is the same. The procedure for breaking off the cap from the new connecting rod is the same as described for the 3.6 L engine (see Section 14).
6. If new pistons are being installed or a short cylinder block is used, the number of marking holes in the cylinder head gasket must be determined (see accompanying illustration), which depends on the maximum value of the protrusion of all pistons relative to the upper surface of the cylinder block. One hole corresponds to a protrusion of 0.91-1.00 mm, two holes - to a protrusion of 1.01-1.10 mm, and three holes - to a protrusion of 1.11-1.20 mm.
42.6 Cylinder head gasket markings
1 Part number
2 Marking holes
3 Production Control Code (doesn't matter)