Crank Mechanism, Dismantling

Crank mechanism, dismantling

Special tools:
999 5746 Holder 999 5746 Holder
999 5679 Oil filter spanner 999 5679 Oil Filter Spanner

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.

Disassembly

Removing oil sump




Remove the screws that hold the oil sump to the intermediate part.
Tap carefully on the side of the oil sump with a plastic mallet
Lift away the oil sump.

Removing the oil pump's suction pipe




Remove the oil channels' O-rings
Remove the screws that hold the suction pipe to the intermediate part.
Wiggle/lift away the suction pipe.
Remove the suction pipe's O-ring.
Check the pipe and the strainer netting.

Checking markings




Install the two previously used flywheel/drive flange screws in the crankshaft's trailing edge.
Turn the crankshaft so that the piston for cylinder 1 ends up in lower dead center (LDC).
Check that the markings on the cap and connecting rods are there and see which way the marking is facing (exhaust-/intake side). Note this.
Mark, as needed, with center punch or digit punch, see: Crank mechanism, assembling Crank Mechanism, Assembling.

Contact face on connecting rod




The contact face between the cap and connecting rod is not machined. The fit takes place using a clean fracture surface.

Caution! If the cap is turned the wrong way and tightened, the structure of the fracture surface will be damaged and the connecting rod must then be discarded.

Note! Clean the fracture surfaces with compressed air before installing caps.

Removing pistons from engine block





Caution! Make sure that the bearing halves are not mixed up. Pay attention to the position of the bearing halves position with regards to the crankshaft's rotational direction.

Remove the screws for the big-end cap.
Lift away the cap. Make sure that the bearing half also comes out.
Install: 999 5746 Holder 999 5746 Holder in the connecting rod and press out the connecting rod/piston.
Hold your hand under piston so that it does not fall to the floor. Make sure that the bearing half also comes out.
Lay the piston with connecting rod so that they can be reinstalled in the right cylinder.
Continue with cylinder 2, 3, 4, 5 as above.

Removing the intermediate part's bolted joint




Carefully pry apart the intermediate part/engine block so that a clearance of approx. 6-8 mm is obtained.
Then carefully tap (at the exhaust side) loose the intermediate part with a plastic mallet.
Lift away the intermediate part. Make sure that the intermediate part's bearing halves also come out.

Caution! Check that the bearing halves are not mixed up.

Pay attention to the position of the thrust bearing's upper half with regards to the crankshaft's rotational direction.
The crankshaft must not rotate.
Make sure that the flywheel/drive flange screws, that were installed earlier, are installed securely. Lift by these screws and the crankshaft's leading edge.
Carefully lift the crankshaft straight up.
Remove the remaining bearing halves.

Note! The bearing covers for the different bearing recesses are not interchangeable.

Removing piston cooling valve/-nozzles




Remove the piston cooling valve in the engine's leading edge.




Remove the piston cooling nozzles.

Cleaning

Cleaning of parts




Clean the gasket surfaces on the engine block, intermediate part and the oil sump.

Warning! If gasket dissolver is used then a closed hood or air extraction shall be used.

Use a razor blade or gasket scraper and/or gasket dissolver, part number 116 1440.