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.

Removal

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
- the screws that hold the suction pipe to the intermediate part.
- the suction pipe by wiggling/lifting
- the suction pipe's O-ring.
Check the pipe and the strainer netting.

Check

Checking markings




Install two old flywheel/drive flange screws at the trailing edge of the crankshaft.
Turn the crankshaft so that the piston for cylinder 1 ends up in lower dead center (LDC).
Check that the markings on the caps 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, B5254T7 Crank Mechanism, Assembling.

Preparatory work

Information about 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! Blow the fracture surface clean with compressed air before reinstalling the cap.

Removal

Removing pistons from the block





Caution! The bearing covers are not interchangeable. Also note the position of the bearing caps for the rotation of the crankshaft.

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 the piston so that it does not fall to the floor, and 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 and 5 as above.

Removing the intermediate part's bolted joint




Carefully pry apart the intermediate part and 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! Make sure that the bearing halves are not mixed up. Also note 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 and drive flange screws, that were installed earlier, are installed securely. Lift by these screws and in 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 and nozzles




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

Removing piston cooling valve and nozzles, continued




Remove the piston cooling nozzles.

Cleaning

Cleaning gasket surface, intermediate part and oil sump





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

Clean the gasket surfaces on the engine block, intermediate part and the oil sump.
Use a razor blade or gasket scraper and/or gasket dissolver 116 1440.