Pistons, connecting rods and cylinder bores

Inspect

Pistons, connecting rods and cylinder bores

$% 12.17.02.03

Disassembly

1. Remove cylinder head gasket. ENGINE - Td5, OVERHAUL, Gasket - cylinder head.
2. Remove connecting rod bearings. ENGINE - Td5, OVERHAUL, Bearings - connecting rods.
3. Remove ridge of carbon from top of cylinder bore.
4. Suitably identify each piston and connecting rod assembly to its respective cylinder bore.
5. Carefully push connecting rod to top of cylinder bore taking care that connecting rod does not contact oil squirt jet or cylinder wall; remove each piston and connecting rod in turn.
6. Using a suitable expander, remove and discard piston rings from pistons.
7. Clean carbon from piston crown and skirt. Do not use abrasives on graphited area of piston skirt, do not use a wire brush or scraper on any part of pistons.
8. Secure connecting rod in a soft jawed vice.
9. Suitably identify each piston to its connecting rod and fitted position of piston on rod.
10. Using suitable circlip pliers, remove and discard 2 circlips securing gudgeon pin.
11. Push gudgeon pin out of piston and connecting rod; remove piston.
12. Suitably identify each gudgeon pin to its respective piston.
13. Repeat above procedures for remaining pistons.

1. Measure cylinder bore for wear at a point 70 mm (2.75 in) from top of cylinder bore: Measurement must be taken from side to side and front to rear. l Cylinder bore diameter = 84.460 to 84.442 mm (3.325 to 3.324 in)

CAUTION: Cylinder bore and ovality must be within the limits given above, no reboring, honing or de-glazing of cylinder bores is permissible; cylinder block must be replaced if bores are worn or excessively scored.

2. Check piston for cracks, burning and damage.
3. Check connecting rods for alignment. Do not attempt to straighten misaligned connecting rods. Ensure small-end lubrication holes in connecting rods are clear.

4. Measure and record diameter of each piston at right angles to gudgeon pin axis and 46 mm (1.81 in) from bottom of skirt l Piston diameter = 84.262 mm ± 0.009 mm (3.317 in ± 0.0003 in)

CAUTION: Measurement point must be on the ungraphited area of the piston.