Crankshaft: Service and Repair
Removing and installing crankshaftTools
Preliminary work
1. Remove engine.
2. Remove cylinder head.
3. Remove oil pan.
4. Remove oil pump.
Removing crankshaft
Note:
^ The color codes of the crankshaft bearings and bearing shells must match!
^ To ensure that the bearings and bearing shells are of a matching class during installation, the bearing numbers are to be written on the backs of the bearings during removal of the main bearing shells with a waterproof felt-tipped pen, due to that fact that the ink markings wear off of the crankshaft journals as well as the main bearing shells.
^ New bearing shells are always to be installed when the engine is repaired.
Belt Pulley Fastening Screw:
Chain Sprocket And Feather Key:
1. Remove chain drive wheel from crankshaft. Unscrew fastening screw on belt pulley. Pull off chain sprocket with drive chain on oil pump; do not lose feather key when doing so.
Clutch Side:
2. Unscrew the four hexagon socket head bolts on the clutch side (M8).
External Cross Bolt Connection:
3. Unscrew the outer cross bolt connection (M8 x 70) in the opposite order to the sequence shown.
Outer Bearing Seat:
4. The figures below indicate the tightening sequence. The fastening screws are undone in the opposite order to the tightening sequence shown. --> Outer bearing seat
Inner Bearing Seat:
5. Undo inner bearing seat in the opposite order to the tightening sequence shown. --> Inner bearing seat
6. Remove lower part of crankcase.
7. Remove any remaining sealant and the old sealing ring in the upper part of the crankcase.
Holding Bridges:
8. Fit holding bridges 9677 on the crankshaft -arrows-.
9. Remove pistons. 'Removing pistons' Rotate engine block in engine stand through 180° so that the crankshaft can be removed.
ATTENTION: Danger of crushing!
^ Risk of crushing your hands when lifting the crankshaft.
--> Hold the very outside of the crankshaft.
--> Wear gloves.°
10. Undo holding bridges 9677 and carefully remove crankshaft upwards.
Installing crankshaft
Note: If no clear markings can be seen after thorough cleaning of the crankshaft and the bearings, the crankshaft and the corresponding bearing shells are to be replaced.
Colour Marking On The Outside:
Note:
^ The bearing shells are available in various tolerance classes. The classes are indicated by the color marking on the outside-refer to Figure-. The color marking must match the corresponding color dot on the crankshaft. The colors are red, yellow and blue and must match between the bearings and the crankshaft.
^ To ensure that the bearings and bearing shells are of a matching class during installation, the bearing numbers are to be written on the backs of the bearings during removal of the main bearing shells with a waterproof felt-tipped pen, due to that fact that the ink markings wear off of the crankshaft journals as well as the main bearing shells.
^ New connecting rod bearings main bearing shells are always to be installed when the motor is repaired.
Correct Position Of The Twist Locks:
1. Insert the bearing shells with the lubricating groove into the upper part of the crankcase. Make sure the twist locks are positioned correctly-see figure-. Then lightly oil the bearing locations.
Sickle-Shaped Washers (Thrust Washers):
2. Insert the sickle-shaped washer (make sure of axial bearing play). To do this, insert the two Insert 3 sickle-shaped washers on the left and 2 on the right (thrust washers) with some grease (000.043.204.17) -see figure-, to prevent the sickle-shaped washers from falling off. Each of the lubricating grooves of the sickle-shaped washers must face outwards.
Turning The Crankshaft:
ATTENTION: Danger of crushing!
^ Risk of crushing your hands when lifting the crankshaft.
--> Hold the very outside of the crankshaft.
--> Wear gloves.
3. Insert crankshaft. The connection flange must point towards the back of the engine. Then secure the crankshaft from falling down using holding bridges 9677. Fix the holding bridges at bearing locations 3 and 5. Screw the fastening screw from the belt pulley at the front into the crankshaft and tighten slightly so that the crankshaft can be turned -see figure-.
4. Turn crankcase by 180° on the assembly support.
5. Install pistons.
6. Turn crankcase again through 180° on the assembly support.
Crankcase Bottom Section:
7. Make sure the crankcase is ready to be screwed in. Check that the sickle discs are positioned correctly. Degrease parting surfaces between top and bottom section of crankcase. A totally grease-free product (e.g. brake cleaner) must be used for this. Then insert a new O-ring at the front of the parting surface-3-.
Centring Pins:
8. Screw the two thin centering pins 9321 into the outer fastening bores on the upper part of the crankcase-see illustration (shown without crankshaft)-.
Twist Locks (Retaining Lugs):
9. Insert bearing shells into lower part of crankcase and lightly oil them. When doing so, ensure that the twist locks (retaining lugs) fit into the appropriate recesses in the lower part of the crankcase.
Note:
^ The liquid sealant must be applied and the screws screwed in within five minutes at most and without interruption.
^ The required tool (torque wrench for 15 Nm (11 ft. lbs.) to 40 Nm (30 ft. lbs.); torque angle wrench; socket wrench E12, E14 and E14) must be ready for use.
^ The threads and head contact surface of the bearing seat screws (M10 x 1.5 and M12 x 1.5) must be oiled.
10. Apply the Drei Bond Silikon 2210 liquid sealant to the lower part of the crankcase as illustrated. The outer surfaces marked -A- must be cleaned after fitting.
11. Place bottom section of crankcase into position. When doing so, make sure that the sealing bead is not destroyed.
Note: Unscrew the centering pins again while securing the lower part of the crankcase.
12. The figures below indicate the tightening sequence. The screws are tightened in four steps. It is essential that the tightening sequence is observed here. The screws must be tightened within five minutes.
Initial tightening 30 ft. lbs.
Initial tightening 16 ft. lbs.
Final tightening 56°
Final tightening 60°
Inner bearing seat
Tightening Sequence, Outer Bearing Seat:
Outer bearing seat
Tightening Sequence, Outer Cross Bolt Connection:
13. Then screw on the outer cross bolt connection (M8 x 70) in the sequence shown Tightening torque 17 ft. lbs..
Clutch Side:
14. Tighten the four hexagon socket bolts on the clutch side (M8 x 35) Tightening torque 17 ft. lbs..
Chain Drive Wheel:
15. Fit chain drive sprocket on the crankshaft. Unscrew fastening screw on belt pulley. Check that the feather keys are fitted correctly and push on the chain sprocket with the oil pump drive chain --> Chain drive wheel. The double-tooth row must be facing forwards.
Subsequent work
1. Install oil pump.
2. Install oil pan.
3. Install cylinder head.
4. Install chain case lid.
5. Install engine.