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

125000939 - 1024A10 CRANK SHAFT - R + R WITH ENGINE REMOVED - CHECK MAIN AND CONNECTING ROD BEARINGAND REPLACE IF NECESSARY

) Proceed with the removal 1020D17 COPERCHIO ANTERIORE tenuta olio albero motore - S.R. e Sost. guarnizioni per motorizzazioni con pompa olio su albero motore lato distribuzione e scambiatore di calore a motore staccato.1. Fit the tool.

	Description	Code
1	Counter-torque	1.820.624.000

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

	Description	Code
-	Counter-torque	1.820.624.000

3. Undo the bolts (3a) and remove the crankcase rear cover (3b) with the oil seal incorporated.4. Fit the tool.

	Description	Code
4	Flange	1.820.618.000

Rotate the crankshaft using the tool fitted previously until the pistons for cylinders 1 and 4 are at B.D.C.

Remove one spark plug for each cylinder to facilitate the rotation of the crankshaft.

5. Undo the bolts (5a) and remove the connecting rod caps (5b) with the half-bearings (5c) for cylinders 1 and 4.Proceed in the same way for the removal of the connecting rod caps for cylinders 2 and 3.

1. Remove the tool.

	Description	Code
1	Flange	1.820.618.000

2. Undo the bolts (2a) and remove the main journal caps (2b) complete with half-bearings (2c).3. Remove the crankshaft.4. Remove the main journal half-bearings.5. Remove the thrust washers.6. Remove the crankpin half-bearings.

Refitting ( Removing

) Visually inspect the condition of the main journal and crankpin half-bearings and replace them if necessary.The size of the main journal half-bearings is given.

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

The size of the connecting rod half-bearings is given.

	Measurement		Value
-	Connecting rod bearing thickness (mm)	Category A	1.536 ÷ 1.540
Category B	1.539 ÷ 1.543
Category C	1.542 ÷ 1.546

Measure the clearances between the main journals and the half-bearings and the crankpins and the half-bearings using the plastic gauge.The clearance between the half-bearings and the journals should correspond to the recommended figures.

	Measurement		Value
-	Main bearing clearance (mm)	crankshaft main journals	0.031 ÷ 0.051

	Measurement		Value
-	Crank pin clearance (mm)	crankshaft crankpins	0.030 ÷ 0.056

If the clearance does not correspond to the recommended values, replace the main journal and/or crankshaft half-bearings following the instructions 1004E20 MOTORE - Scomp. e Ricomp. a seguito Op. 1004E10 - Lavaggio e controllo parti smontate - Riattacco testa cilindri e coppa olio - Non comprende interventi su testa cilindri e gruppo organi ausiliariFit the crankpin half-bearings.Fit the main journal half-bearings.Fit the crankshaft in the crankcase.Fit the thrust washers on the 3rd main journal.Fit the main bearing caps complete with half-bearings.

The bearing caps have progressively numbered references (from zero to four starting from the front of the engine) which define the fitting position.

Tighten the bolts fixing the bearing caps to the recommended torque.

	Fastening	Component	Ø	Value(daNm)
-	-	-	-	-

Use the torque wrench for the angular tightening of the bearing cap bolts.

	Description	Code
-	Torque wrench	1.860.942.000

1. Fit the crankcase rear cover (1a) with the oil seal incorporated and tighten the bolts to the recommended torque.

	Fastening	Component	Ø	Value(daNm)
1b	-	-	-	-

Fit the tool.

	Description	Code
-	Flange	1.820.618.000

Rotate the crankshaft until cylinders no.1 and 4 are at B.D.C.3. Place the connecting rod caps (3a) in their seats complete with half-bearings (3b) and secure them by tightening the bolts (3c) to the recommended torque.

Fit the connecting rods so that the number stamped on each rod faces towardt he same side as the number stamped on the big end.

	Fastening	Component	Ø	Value(daNm)
3c	-	-	-	-

Use the torque wrench for the angular tightening of the crank pin cap bolts.

	Description	Code
-	Torque wrench	1.860.942.000

4. Fit the tool.

	Description	Code
4	Counter-torque	1.820.624.000

5. Fit the flywheel (5a) and secure it by tightening the bolts (5b) to the recommended torque.

	Fastening	Component	Ø	Value(daNm)
5b	-	-	-	-

Remove the tool.

	Description	Code
-	Counter-torque	1.820.624.000

Proceed with the refitting 1020D17 COPERCHIO ANTERIORE tenuta olio albero motore - S.R. e Sost. guarnizioni per motorizzazioni con pompa olio su albero motore lato distribuzione e scambiatore di calore a motore staccato.