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! 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, B5254T7 Tightening Torque.
Cleaning
Make sure that all included parts are well cleaned. Blow clean the oil channels in the block, the intermediate part and the sump.
Installation
Installing piston cooling valve and nozzles
Install the piston cooling nozzles. Tighten according to: Tightening torque, B5254T7 Tightening Torque.
Installing piston cooling valve and nozzles, continued
Install the piston cooling valve. Use new seal washer. Tighten according to: Tightening torque, B5254T7 Tightening Torque.
Check
Classification of main bearings
Wipe clean the bearing positions in the block and intermediate part.
Check that the parts are clean and free from damage.
Check classification of the block and crankshaft.
The classification marking is at the trailing edge of the block and crankshaft. The classification shall be read from the digit 1 to 7 and the first letter after the digit 1 corresponds to the classification of main bearing 1.
The bearing positions are numbered starting at the leading edge of the engine.
Selecting bearing
Install the main bearings in the engine block and in the intermediate part according to the table.
The thrust bearing is placed at bearing position 5.
Caution! When reusing old bearing covers, ensure that they are correctly positioned for the direction of rotation of the crankshaft.
Example: The marking on the block at bearing position 1 is B. The marking on the crankshaft at corresponding bearing position is C.
This gives a red-marked bearing in the block and a yellow-marked in the intermediate part.
Note! The thickest of the bearing halves shall always be installed in the intermediate part. This is to obtain the straightest possible center line.
Cleaning
Applying liquid gasket and oil
Wipe the surfaces dry.
Apply liquid gasket 11 61 059 on the intermediate part. The surface shall be completely covered without any excess. Use: 951 2767 Roller 951 2767 Roller.
Carefully lube all bearing shells and the thrust bearing surface with oil.
Installation
Tightening intermediate part
Install two old flywheel/drive flange screws at the trailing edge of the crankshaft.
Lift by these screws and the leading edge of the crankshaft.
Carefully lay the crankshaft into place in the block.
The crankshaft may not be rotated before the intermediate part is torque-tightened.
Lay the intermediate part into place.
Lube all screws with oil and install them.
Install the intermediate part with the screws on the exhaust side at bearing position 2 and 5.
Tighten down the intermediate part against the block.
Caution! The M8-screws on the exhaust side have two lengths.
Note! Use new M10 screws.
Tighten the screws according to: Tightening torque, B5254T7 Tightening Torque following order:
Tighten the screws in sequence from the middle and out.
Marking of connecting rod, if any
Assemble the connecting rod. Check that the cap is turned facing the right way. Tighten according to: Tightening torque, B5254T7 Tightening Torque.
Secure the connecting rod's big-end in a vice with soft jaws (copper or aluminum).
Mark both halves with cylinder number.
Use a digit punch or center punch.
Selecting piston
For every cylinder there is a classification letter stamped (C, D, E) on the top of the engine block.
First letter after the digit 1 corresponds to the classification of the cylinder bore in cylinder 1 and is then followed by cyl. 2, 3, 4, 5.
Selection of piston is controlled by the cylinder bore's classification. Example: Cylinder classification D shall have piston marked D, and so on.
Installing piston rings
Use piston ring pliers.
Turn the piston rings so that the piston ring openings are displaced as shown in the figure.
A=Compression ring. The text on the piston ring shall face up.
B=Scraper ring. The bevel shall face down.
C=Oil ring. Three parts equilateral.
First install the expander ring (C), then the two upper rings over the expander ring.
Caution! Ensure that the piston rings can be turned easily.
Note! Incorrect installation gives increased oil consumption.
Assembly
Assembling pistons and connecting rods
There is an arrow marking on top of the piston. This shall be turned to face forward in the engine block.
The connecting rods are symmetrical and can be turned arbitrarily. However, marked connecting rods shall be turned to face the same way.
Assemble connecting rod and piston with the piston pin.
Check that the classification of each cylinder and piston diameter as well as any numbering of the connecting rod correspond.
Install the piston pin's two lock rings. Check that the lock rings are positioned correctly in the piston. The opening shall be positioned in the vertical line.
Caution! The snap ring can easily come off. Wear protective goggles!
Wipe clean at the bearing position in the connecting rod and the cap.
Install the bearing shells and center them in the bearing position.
Caution! If previously used bearing shells are used, they must be placed as before. Ensure that they are correctly positioned in relation to the direction of rotation of the crankshaft.
Installation
Installing pistons in cylinder bores
Use piston ring compressor.
Lube the cylinder bores, pistons and bearing shells with oil.
Turn the crankshaft so that the crank pin is in lower dead center for the cylinder that the piston is to be installed in.
Make sure that the engine is suspended in such a way that the cylinder bores are as vertical as possible.
Note! The piston's arrow (on top of the piston) shall point forward. Make sure that the classification matches.
Carefully press/tap down the piston (e.g., with the handle of a hammer).
When the piston has released the piston ring compressor, turn the engine 180° in the stand.
Install: 999 5746 Holder 999 5746 Holder in the connecting rod.
Tighten the connecting rod until it is fixated against the big-end bearing journal.
Tightening connecting rod's cap
Install the cap. Check that the marking, if any, matches.
Lube new screws with oil and install them. Tighten according to: Tightening torque, B5254T7 Tightening Torque in two steps:
Check that the connecting rod can be moved slightly sideways.
Note! The crankshaft must not be rotated before the connecting rod cover has been tightened.
Installing oil pump's suction line
Install a new seal ring on the suction line.
Carefully press down the suction line in the intermediate part.
Check that the seal ring is positioned correctly.
Tighten.
Install new seal rings for the oil channels to the oil sump.
Installing oil sump
Wipe the surfaces dry.
Apply liquid gasket 11 61 059 on the oil sump. Use: 951 2767 Roller 951 2767 Roller.
The surface must be completely covered without any excess.
Fit the sump 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 sump's trailing edge and forward.
Installing rear crankshaft seal
Use: 999 1801 STANDARD SHAFT 999 1801 Standard Shaft and 999 5676 Drift replaced by 9997174 999 5676 Drift Replaced By 9997174.
Lube the drift's sliding surface with oil and fit the seal on the drift.
Tap in the seal until the drift stops against the block.