1024A10 CRANK SHAFT - R + R WITH ENGINE REMOVED - CHECK MAIN AND CONNECTING ROD BEARINGAND REPLACE IF NECESSARY - Alfa - 156 - eLearn

3239074 - 1024A10 crank shaft - r + r with engine removed - check main and connecting rod bearingand replace if necessary

Record the main bearing half thickness.

	Measurement		Value
-	Crankshaft bearing thickness (mm)	Category B	1.839 - 1.843
Category C	1.842 - 1.846
Classe A	1.836 - 1.840

Record the main bearing half thickness.

	Measurement		Value
-	Thickness (mm)	Category B	1.530 - 1.534
Category C	1.533 - 1.537
Classe A	1.527 - 1.531

Removing ( Refitting

) - 1020D17 engind front cover - r r . 1. Fit the flywheel lock.

	Name	Country
1	Counter-torque	1.860.846.001

2. Undo the fixing bolts (2a) and remove the clutch (2b).

1. Undo the fixing bolts (1a) and remove the engine flywheel (1b).

1. Remove the flywheel lock.

	Name	Country
1	Counter-torque	1.860.846.001

2. Undo the bolts (2a) and remove the engine flywheel protection (2b).

1. Undo the bolts (1a) and remove the rear crankshaft oil sealling cover (1b).Fit the tool.

	Name	Country
-	Flange	1.860.815.000

Rotate the crankshaft using the tool fitted previously until the cylinder concerned is at B.D.C.1. Undo the bolts (1a) and remove the connecting rod cap (1b).2. Remove the lower big end bearing shell.Proceed in the same way with removing the connecting rod caps and the half-bearings for the remaining cylinders.3. Undo the bolts (3a) and remove the bearing caps (3b).4. Remove the lower main journal half-bearings.5. Remove the crankshaft.6. Remove the upper connecting rod half-bearings.7. Remove the upper main journal half-bearings.8. Remove the thrust washers from the 4th main journal support.

Refitting ( Removing

) Visually inspect the condition of the main journal and connecting rod half-bearings and, if necessary, replace them.Record the main bearing half thickness.

	Measurement		Value
-	Side crankshaft bearing thickness (mm)	Category B	1.836 -1.844
Category C	1.843 -1.849
Classe A	1.831 -1.837

Record the main bearing half thickness.

	Measurement		Value
-	Connecting rod half bearing thickness (mm)	Category B	1.530 ÷ 1.534
Category C	1.533 ÷ 1.537
Classe A	1.527 ÷ 1.531

Measure the clearance between main journals and bearing halves and crankpins and bearing halves using Plastic Gauge.The clearance between bearing halves and journals must be within specified limits.

	Measurement		Value
-	Big end bearing clearance (mm)	crankshaft big end bearings	0.030 ÷ 0.056

If the clearance is not within specified limits, replace the main bearings and/or connecting rod bearings as indicated in - 1004E20 engine - dismantle and re-build following operation 1004e10 - wash and check dismantled parts - re-fit cylinder head and oil sump - does not include repairs to cylinder head and auxiliary unit . Fit the upper main journal half-bearings in the cylinder block/crankcase.Fit the upper connecting rod half-bearings on the connecting rods.Fit the crankshaft on the cylinder block/crankcase.Fit the thrust washers on the 4th main journal support.1. Fit the bearing caps.

The bearing caps have progressive notches (from zero to five starting from the front of the engine) which define their fitting position.

1. Tighten the bearing cap bolts (1a) to the recommended torque using the angular tightening tool (1b).

	Fastening	Component	Ø	Value(daNm)
1a	Bolt	BIG END BEARING CAPS	M12	(Engine block side) 2.5 + 100°

	Name	Country
1b	Protractor	1.860.942.000

Rotate the crankshaft using the tool fitted previously until the cylinder concerned is at B.D.C.Fit the connecting rod cap, complete with half-bearing, and fix it using the bolts without tightening them.

The connecting rod caps are fitted so that the number stamped on them is facing the same side as the one stamped on the big end (inlet side).

Continue in the same way when fitting the connecting rod caps for the remaining cylinders.1. Tighten the bolts (1a) for the connecting rod caps to the recommended torque, using the angular tightening tool (1b).

	Fastening	Component	Ø	Value(daNm)
1a	Bolt	BIG END BEARING CAPS	M9	2.0 + 60°

	Name	Country
1b	Protractor	1.860.942.000

Remove the tool.

	Name	Country
-	Flange	1.860.815.000

1. Fit rear engine block cover (1a) with integrated oil sealing ring and tighten relevant bolts (1b).

	Fastening	Component	Ø	Value(daNm)
1b	Bolt	FLYWHEEL SIDE COVER	M6	(Engine block side) 0.9 ÷ 1.2

1. Fit the engine flywheel shield (1a) and tighten the fixing bolts (1b).

Fit the tool.

	Name	Country
-	Counter-torque	1.860.846.001

1. Fit the engine flywheel (1a) and fix it tightening the bolts (1b) to the recommended torque.

	Fastening	Component	Ø	Value(daNm)
1b	Bolt	FLYWHEEL	M12	14.7 - 21.2

Fit the clutch locating tool.

	Name	Country
-	Tool for centering clutch	1.870.081.000

1. Fit the clutch assembly in its seat.2. Tighten the clutch bolts.

	Fastening	Component	Ø	Value(daNm)
2	Bolt	CLUTCH ASSEMBLY	M8	2.8

Remove the tool.

	Name	Country
-	Tool for centering clutch	1.870.081.000

3. Remove the flywheel lock.

	Name	Country
3	Counter-torque	1.860.846.000

- 1020D17 engind front cover - r r