Crank Mechanism, Reassembly

CRANK MECHANISM, REASSEMBLY





Classification of crankshaft main bearings
- Clean main bearing seats.
- Check that components are clean and undamaged.
- Check classification on cylinder block and crankshaft.

Each main bearing seat is marked with the cylinder number and a classification letter for the block and crankshaft. Use the table below to select the right bearing.




Selecting bearing
- Install main bearing in cylinder block as in table.
- Oil bearing shells liberally on crankshaft side.
- Install flanged shells in rearmost position.

E.g.: Classifying no.1 bearing.
Marking on block is B.
Marking on crankshaft is C.
Install a red bearing in the block and a yelloW bearing in the intermediate section.




Intermediate section
- Apply liquid sealing compound (1 161 059-9) to intermediate section. Cover entire surface, but do not allow to overflow, as this may block ducts and bolt holes.
- Use short-haired roller 9511205.
- Place bearing shells in intermediate section (make sure bearing shells are dry between bearing and block. otherwise bearing may rotate along with crankshaft).
- Oil bearing shells and flange bearing (furthest back) generously.




Install crankshaft
- Install crankshaft. Do not turn crankshaft before intermediate section has been tightened.
- Put intermediate section in position.
- Tighten intermediate section/crankshaft bolts in five stages in numerical order as shown in picture. Each stage must be complete before starting the next.
1. Tighten all M10 bolts to 20 Nm (15 ft lb)
(skip M8 and M7 until stages 3 and 4.)
2. Tighten M10 bolts to 45 Nm (33 ft lb)
3. Tighten M8 bolts to 24 Nm (18 ft lb)
4. Tighten M7 bolts to 17 Nm (13 ft lb)
5. Finally, tighten M10 bolts 90°

Max. length of M10 bolts 118mm




Measure crankshaft end float
- Check that crankshaft turns smoothly.
- Measure end float.
- Use dial gauge, magnetic plate 999 5971 and magnetic stand 999 9696.

End float: 0.08-0.19 mm




Install crankshaft rear seal
- Use standard handle 999 1801 and assembly tool 999 5430.
- Oil mating surfaces between seating flange and seal, and between seal lips. Place seal on drift.
- If there are wear marks on crankshaft, push seal further in than before by removing a spacer from the tool.
- Tap seal in until drift meets crankshaft.




Assemble pistons and conrods
- Arrow on piston crown must point forwards, i.e. towards timing belt end of engine. Number markings on conrods must face towards intake side of block (starter motor side).

Piston, replacement: Later Volvo 960 models have two types of piston, which differ in terms of their upper compression rings. Version 1 can be replaced by version 2 wfthout having to replace all pistons; but version 2 must not be replaced by version 1.

Conrod, replacement: Conrods are symmetrical and can be used either way round.
Markings: Install conrod (tighten bolts to 20 Nm (15 ft lb)) and check that bearing cap is pointing in the right direction. Put big end in a vice wfth copperinsens or similar. Mark both halves wfth the cyllnder number using a number punch or die.

Note: Insert circlip and check that ring springs apart and locks in groove. Circlip opening should point downwards.




Install piston rings
- Use piston ring pliers 998 5424. Turn piston rings so gaps are approx. 120° apart.
A. Upper compression ring: Text facing upwards
B. Lower compression ring: Groove facing downwards
C. Oil scraper ring: Text facing upwards
- Clean and dry bearing seats in conrods and caps.
- Install bearing shells in conrods and caps.
- Install guide pins 999 5502.

Important: If reusing original bearing shells, components must be located in original positions.




Install pistons in bores
- Use piston ring compressor 115 8281.
- Oil cylinder bores, pistons and bearing shells.
- When fitting each piston, turn crankshaft so crank pin is at its lowest position to fit the piston in.
- Check that piston classification is correct.
- Press piston down (e.g. with hammer shaft).

Note: Arrows on piston crown must point towards front, i.e. timing belt, end of engine.




Install bearing caps
- Remove guide pins (5502) and install caps.

Note: Do not turn crankshaft until conrod bearing caps have been tightened.

- Check that con rod and bearing cap markings match.
- Use new bolts. Oil bolts, and tighten in two stages:
1. 20 Nm (15 ft lb)
2. Plus 90°
- Check that conrods are free to move laterally.




Install oil pump suction pipe
- Put gasket on pipe.
- Reconnect pipe.
- Tighten to 17 Nm (13 ft lb).
- Install new oil passage seals.




Install oil sump
- Apply liquid sealing compound (P/N 1 161 059-9) to sump. Use short-haired roller 951 1205.

Important: Insert four bolts and align sump flush with rear face of block. Permitted tolerance = ±0.025 mm.

- Tighten bolts back and front to 17 Nm (13 ft lb).
- Install new oil filter.