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.

Preparatory work

Tightening torque
For tightening torques not in the text, see Specifications. Tightening Torque.

Cleaning
Make sure that all included parts are well cleaned.
Blow clean the oil channels in the engine block, the intermediate part and the oil sump.

Assembly

Installing piston cooling valve/nozzles




Install the piston cooling nozzles. Tighten according to: Tightening torque Tightening Torque.




Install the piston cooling valve. Use new seal washer. Tighten according to: Tightening torque Tightening Torque.

Classification of main bearings




Wipe clean the bearing positions in the cylinder block and intermediate part.
Make sure that the parts are clean and free from damage.
Check the classification of the cylinder block and crankshaft.
The classification marking is at the trailing edge of the engine block and crankshaft. The classification shall be read from the digit 1 to 7. The first letter after the digit 1 corresponds to the classification of main bearing 1. The bearing positions are numbered starting at the engine's leading edge.

Selecting bearing





Install the main bearings in the engine block and intermediate part, according to table.
The thrust bearing is placed at bearing position 5.

Caution! When reusing old bearing halves, make sure when installing the thrust bearing with regards to the crankshaft's rotational direction.

For example, the marking on the engine block at bearing position 1 is B. Then the marking on the crankshaft at the corresponding bearing position is C.
This gives a red-marked bearing in the engine 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.

Intermediate part




Wipe the surfaces dry.
Apply liquid gasket, part number 116 1059 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.

Tightening intermediate part




Install the two old flywheel/drive flange screws in the crankshaft's trailing edge.
Also install screws in the crankshaft's leading edge.
Carefully lay the crankshaft into place in the block.
The crankshaft may not be rotated before the intermediate part is tightened down with the correct torque. Fit the intermediate part.
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.

Caution! Pay attention, the M8-screws on the exhaust side have two lengths.

Note! Use new M10-screws.

Tighten all screws according to Tightening torque Tightening Torque.
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 Tightening Torque.
Secure the connecting rod's big-end in a vice with soft jaws (copper or aluminum).
Mark both halves with a 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 cylinder 2, 3, 4, 5.
Selection of piston is controlled by the cylinder bore's classification. Fort example, cylinder classification D shall have a piston marked with the letter D.

Installing piston rings




Use piston ring pliers.
Turn the piston rings so that the piston ring openings are displaced, see 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! The oil consumption increases in case of incorrect installation.

Assembling pistons and connecting rods




There is an arrow marking on the 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/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 vertically.

Caution! The lock 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 reusing previously used bearing shells, they must be installed in the same position as before.

Also pay attention when installing with regards to the crankshaft's rotational direction.

Installing pistons in cylinder bores




Use a 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 arrow on top of the piston must point forwards. Ensure that the classifications correspond!

Carefully press/tap down the piston (e.g., with the handle of a hammer).
When the piston has released the piston ring compressor, then 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 and check that the marking, if any, matches.
Lube the new screws with oil and install them. Tighten according to: Tightening torque Tightening Torque.
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 and tighten.
Install the new seal rings for the oil channels to the oil sump.

Installing oil sump




Wipe the oil sump's surfaces dry.
Apply liquid gasket, part number 116 1059, on the oil sump. Use 951 2767 Roller 951 2767 Roller
The surface shall be completely covered without any excess.
Fit the sump and install all screws.

Caution! Check that the trailing edge of the oil sump is in line with the trailing edge of the engine block. Permitted tolerance is ± 0.025 mm. Use a steel ruler and a feeler gauge.

Tighten the screws from the oil 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 engine block.