Engine body - Service procedures

5

Check the axial and the radial clearance of the camshaft. Correct clearance: see Workshop Manual, Technical Data for each engine concerned.

6

Check the axial and the radial clearance of the intermediate gear: Correct clearance: see Workshop Manual, Technical Data for each engine concerned.

7

Check the tooth flank clearance. See Workshop Manual, Technical Data for each engine concerned.

11

Adjust the valves, and fit the valve covers.

12

Fit the remaining equipment. Where necessary top up with lubricant and coolant. Test run the engine.

Crankshaft, removing

(With engine removed)

Special tool: 2655

1

Drain the oil.

2

Remove the oil pan. Remove the oilstrainer and the pressure pipe for the oil pump.

8

Fit the timing gear cover. See Timing gear cover, assembly

9

Lubricate the contact surface of the tappets to the camshaft with molybdenum disulphide and oil in the tappets bore in the cylinder block. Install the tappets in the correct order.

10

Install the push rods and rocker mechanism.

Remove the crankshaft pulley, vibration damper, polygon hub and timing gear cover. See Timing gear cover, removing

4

Remove the flywheel and flywheel cover.

5

Remove the main bearing and big end caps. (The lubricating oil pump is removed together with the front main bearing cap). Lift out the crankshaft.

Crankshaft, inspection

The inspection of the crankshaft must be extremely thorough to avoid unnecessary overhauling. To determine overhauling requirements, the following applies:

A. Measure the bearing journals and pins for out-ofroundness, wear and taper. See Workshop Manual, Technical Data for each engine concerned.

B. Assess the surface damage.

For nitro-carburized shafts, the following applies: What on an induction-hardened crankshaft may be regarded as scoring due to dirt can in the case of a nitrocarburized shaft be the normal surface finish as on a new crankshaft. The markings show up very clearly on a shaft that has been in use because of the shiny bearing surfaces. Very small particles can loosen from the thin surface layer after the shaft has been in use for some time.

This phenomenon is easily confused with scoring caused by dirt, but close inspection will show that the marks do not go entirely round the bearing journal and have uneven edges. These slight defects do not necessarily require the regrinding of the crankshaft. Usually it is enough to polish the bearing journals lightly with emery cloth and fit new bearings.

C. Measure crankshaft alignment (throw).

The crankshaft should be placed on either a pair of Vblocks, under 1st and 7th main bearing journals, or fixed between stocks. Measurements should be made on the 4th main bearing.

The following applies with regard to the values measured:

1

Less than 0.2 mm (0.0079") – no alignment necessary if wear and surface damage do not necessitate regrinding.

2

Between 0.2–0.7 mm (0.0079–0.0276") – can be aligned, but care must be taken to avoid over-alignment.

Note! Do not align more than absolutely necessary.

3

More than 0.7 mm (0.0276") – the shaft must be scrapped due to risk of cracking during alignment.

D. Checking for cracks.

Checking must be carried out after alignment and before and after grinding.

To check, use a magnetic powder test of type Magnaglo, i.e. fluorescent powder which can be seen under ultraviolet light.

Refer to crack detection, manufacturer's instructions on the method to be adopted. When assessing the cracks, the following applies: