Crank, Pistons and Rods, Reassembly
Special Tools:
- Standard Handle tool No. 999 1801, or equivalent
- Installation tool No. 999 5430, or equivalent
- Base tool No. 999 5971, or equivalent
- Magnetic Stand tool No. 999 9696, or equivalent
Universal Tools:
- Piston Ring Compressor tool No. 115 8281, or equivalent
- Roller tool No. 951 1205, or equivalent
- Piston ring compressor tool No. 998 5424, or equivalent
NOTE: For additional information on special tools and equipment used in this procedure, refer to "Tools For Engine Reconditioning". Tools and Equipment
Procedure
1. Classification of crankshaft main bearings:
- Clean main bearing seats.
- Check that components are clean and free of damage.
- Check classification markings on cylinder block and crankshaft.
NOTE:
- Each bearing seat is marked with the cylinder no. and a classification letter for the block and crankshaft.
- Use the table below to select the right bearing shells.
2. Selecting bearing shells:
- Install main bearings in cylinder block (See table).
- Oil bearing shells liberally on crankshaft side.
- Install flanged shells in rear most position.
- Example: Classifying no. 1 bearing.
Marking on block is B.
Marking on crankshaft is C.
Accordingly, use a red shell in the block and a yellow shell in the intermediate section.
3. Intermediate section:
- Apply liquid gasket compound, part No. 1 161 059-9, or equivalent to intermediate section.
Cover surface completely but do not allow to overflow, as this may block channels and bolt holes.
- Use a short-haired roller tool No. 951 1205, or equivalent.
- Put bearing shells in intermediate section.
Bearing seats must be dry.
- Oil bearing shells and flanged shells (at back) liberally.
4. Install crankshaft:
- Install crankshaft.
Do not rotate it until intermediate section is tightly in place.
- Install intermediate section.
- Tighten intermediate section and crankshaft bolts in 5 stages in sequence from the center towards ends.
Complete each stage before starting the next.
Skip 8 mm and 7 mm bolts until stages 3 and 4.
1st Stage: Tighten all 10 mm bolts to 20 Nm (15 ft lb)
2nd Stage: Tighten 10 mm bolts to 45 Nm (33 ft lb)
3rd Stage: Tighten 8 mm bolts to 24 Nm (18 ft lb)
4th Stage: Tighten 7 mm bolts to 17 Nm (13 ft lb)
5th Stage: Finally, tighten 10 mm bolts through 90°
NOTE: Max. Length of 10 mm bolts 118 mm.
5. Measure axial clearance:
- Check that crankshaft rotates smoothly.
- Measure crankshaft axial clearance.
- Use dial gauge, magnetic plate tool No. 999 5971 and magnetic frame tool No. 999 9696, or equivalents.
- Axial clearance: 0.08-0.19 mm
6. Install crankshaft rear seal:
- Use standard handle tool No. 999 1801 and assembly tool No. 999 5430, or equivalents.
- Oil mating surfaces between seating flange and seal, and between seal lips. Place seal on drift.
- If there are any wear marks on the crankshaft, push seal further into the flange than before by removing a spacer ring from the tool.
- Tap seal in until drift meets crankshaft.
7. Assemble pistons and connecting rods:
- Arrow on piston crown must point towards front, i.e. timing belt, end of engine.
Numerical markings on connecting rod must face towards intake side of block (starter motor side).
NOTE:
- Install wrist pin circlip and check that the circlip springs apart and locks in the groove.
- The circlip opening should point downwards.
CAUTION:
- Pistons, replacement:
Later Volvo 850s have two different types of piston, which differ in terms of the upper compression ring.
Version number 1 can be replaced by version number 2 without having to replace all the pistons; but version number 2 can not be replaced by version number 1.
- Connecting Rods, replacement:
Connecting Rods are symmetrical and can face either way round.
- Markings:
Assemble connecting rod (tighten bolts to 20 Nm) and check that bearing end cap is pointing the right way.
Put the big end in a vice with copper spacers or similar.
Mark both halves with the cylinder number using a number punch or die.
8. Install piston rings as follows:
- Use piston ring pliers tool No. 998 5424, or equivalent.
- Turn rings so gaps are approx. 120° apart.
- A. Compression ring: Text upwards
- B. Scraper ring: Bevel downwards
- C. Oil scraper ring: Text upwards
NOTE: Piston rings, dimensions, refer to Crank, Pistons and Rods, Measurement.
- Clean/dry bearing seats in connecting rods and bearing caps.
- Install bearing shells in connecting rods and bearing caps.
- Install guide pins tool No. 999 5502, or equivalent.
CAUTION: If re-using original bearing shells, components must be located in original positions.
9. Fit pistons in bores:
- Use piston ring compressor tool No. 115 8281, or equivalent.
- Oil cylinder bores, pistons and bearing shells.
- When fitting each piston, turn crankshaft so crank pin for that piston is in its lowest position.
- Check that piston classification is correct.
- Press piston into bore (using a hammer shaft).
NOTE: Arrow on piston crown must point towards front, i.e. timing belt, end of engine.
10. Install bearing end caps:
- Remove guide pins tool No. 999 5502, or equivalent and install caps.
NOTE:
- Crankshaft must not rotate until all connecting rods/bearing caps have been tightened.
- Bearing shells may change position.
- Check that markings on crankshaft and bearing caps line up.
- Use new oiled bolts.
- Tighten them in two stages:
1st Stage: 20 Nm (15 ft lb)
2nd Stage: Turn through 90°
- Check that connecting rods are free to move laterally.
11. Install oil pump suction pipe:
- Put gasket on pipe.
- Reconnect pipe.
- Tighten to 17 Nm (13 ft lb).
- Use new oil channel seals.
12. Install oil pan:
- Apply liquid gasket compound part No. 1 161 059-9, or equivalent on pan with short-haired roller tool No. 951 1205, or equivalent.
NOTE:
- Insert four bolts and align pan flush with rear face of block.
- Permitted tolerance = ±0.025 mm.
- Use calipers and feeler gauges.
- Tighten bolts from front and rear, tighten to 17 Nm (13 ft lb).
- Install new oil filter.