Crank Mechanism, Assembling
Crank mechanism, assembling
Special tools:
951 2767 Roller 951 2767 Roller
999 1801 STANDARD SHAFT 999 1801 Standard Shaft
999 5676 Drift replaced by 9997174 999 5676 Drift Replaced By 9997174
999 5746 Holder 999 5746 Holder
Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information in the illustrations is always correct.
Tightening torque
For tightening torques not in the text, see Tightening torque, B5234T9 Tightening Torque.
Cleaning
Ensure that the all components are completely clean.
Blow clean the oil ducts in the block, intermediate section and oil pan.
Installing the piston cooling valve and nozzles
Install the piston cooling nozzles. Tighten to 17 Nm .
Install the piston cooling valve. Use a seal washer. Tighten to 38 Nm .
Classification of main bearings
Wipe clean the bearing recesses in the block and the intermediate section.
Check that the components are clean and undamaged.
Check the classification of the block and crankshaft.
The classification marking is at the rear edge of the block and the crankshaft. The classification is read from digits 1 to 7. The first letter after digit 1 is the classification of main bearing 1. The bearing positions are numbered starting at the front of the engine.
Selecting bearings
Install the main bearings in the cylinder block and the intermediate section. See the table.
The axial bearing is positioned at bearing recess 5.
Caution! When reusing old bearing covers, ensure that they are correctly positioned for the direction of rotation of the crankshaft.
For example: The marking on the block at bearing recess 1 is B. The marking on the crankshaft at the corresponding bearing recess is C.
Therefore the bearing in the block is marked red and the bearing in the intermediate section is marked yellow.
Note! The thickest of the bearing caps must always be installed in the intermediate section. This is keep the center line as straight as possible.
The intermediate section
Wipe the surfaces dry.
Apply liquid gasket 11 61 059 to the intermediate section. The surface must be completely covered without any excess. Use roller 951 2767 Roller 951 2767 Roller
Thoroughly lubricate all the bearing shells and the surface of the axial bearing.
Tightening the intermediate section
Install the two old screws for the flywheel and carrier plate at the rear edge of the crankshaft.
Lift these and the front of the crankshaft.
Carefully position the crankshaft in the block.
The crankshaft must not be turned before the intermediate section has been torque tightened. Position the intermediate section.
Lubricate and install all the screws.
Note! Use new M10 screws.
Install the intermediate section and the screws on the exhaust side at bearing recesses 2 and 5.
Caution! The M8-screws on the exhaust side are two different lengths.
Pull down the intermediate section.
Tighten the screws in the following order:
1. All M10 screws 20 Nm
2. All M10 screws 45 Nm
3. All M8 screws 24 Nm
4. All M7 screws 17 Nm
5. Angle-tighten all M10 screws 90°
Tighten the screws in sequence from the center and outwards.
Marking the connecting rod (where applicable)
Assemble the connecting rod. Check that the cover is facing the correct direction. Tighten to 20 Nm .
Secure the large end of the connecting rod in a vise with soft jaws (copper or aluminum).
Mark both halves with the cylinder number. Use a center punch or number punch.
The bearing shell with the black color coding on the side must be installed in the connecting rod.
Installing piston rings
Use piston ring pliers.
Turn the piston rings so that the openings are offset as illustrated.
A=Compression ring. The text on the piston ring must be upwards.
B=Scraper ring. Chamfered edge must face downwards.
C=Oil ring. Three sections, identical on all sides.
First install the expander ring (C), then the two other rings over the expander ring.
Caution! Ensure that the piston rings can be turned easily.
Note! Incorrect positioning increases oil consumption.
Assembling pistons and connecting rods
There is an arrow on top of the piston. This must be turned forwards in the cylinder block.
The connecting rods are symmetrical and can be turned freely. Marked rods however must be turned in the same direction.
Assemble the connecting rod and piston with the piston pin.
Check that the classification and any numbering for each cylinder and piston diameter correspond.
Install both the snap rings on the piston pin. Check that the snap rings are positioned correctly in the piston. The opening must be vertical.
Warning! The snap ring can easily come off. Wear protective goggles!
Wipe clean around the bearing recess in the connecting rod and the cap.
Install the bearing shells.
If new bearing shells are used, these must be checked for color coding.
Note! The bearing shell with a black color coding on the side must be installed in the connecting rod.
Caution! If reusing the bearing shells, they must be installed in the same position as before. Ensure that they are correctly positioned in relation to the direction of rotation of the crankshaft.
Installing the pistons in the cylinder bores
Use a cylinder ring compressor.
Lubricate the cylinder bore, the pistons and the bearing shells.
Turn the crankshaft so that the connecting rod pin is at bottom dead center (BDC) for the cylinder the piston is to be inserted in.
Ensure that the engine is in a position where the cylinder bore forms as vertical a line as possible.
Note! The arrow on top of the piston must point forwards. Ensure that the classifications correspond!
Carefully press or tap the piston down (using the shaft of a hammer or similar).
When the piston releases from the piston ring compressor, turn the engine 180° in the stand.
Install tool 999 5746 Holder 999 5746 Holder in the connecting rod.
Pull the connecting rod until it secures against the big end journals.
Tightening the connecting rod cover
Install the cover. Check that any markings correspond.
Lubricate and install new seals. Tighten in two stages:
1. 20 Nm .
2. Angle-tighten 90° .
Check that the connecting rod can be moved sideways.
Note! The crankshaft must not be rotated before the connecting rod cover has been tightened.
Installing the oil pump suction pipe
Install a new sealing ring on the suction pipe.
Carefully press the suction pipe down into the intermediate section.
Check that the sealing ring is correctly positioned.
Tighten.
Install new sealing rings for the oil ducts to the oil pan.
Installing the oil pan
Wipe the surfaces dry.
Apply liquid gasket 11 61 059 to the oil pan. Use roller 951 2767 Roller 951 2767 Roller.
The surface must be completely covered without any excess.
Position the pan and install all screws
Caution! Check that the rear edge of the oil pan is in line with the rear edge of the cylinder block. Permissible tolerance ± 0.025 mm. Use a steel ruler and feeler gauge.
Tighten the screws from the rear of the pan and forward.
Installing the oil cooler
Install
- new sealing rings in the oil pan
- the oil cooler. Tighten
- the oil filter.
Installing the rear crankshaft seal
Use standard handle 999 1801 STANDARD SHAFT 999 1801 Standard Shaft and drift 999 5676 Drift replaced by 9997174 999 5676 Drift Replaced By 9997174.
Lubricate the drift face and thread the sealing ring onto the drift.
Tap in the seal until the drift bottoms against the block.