Cylinder Block Assembly: Service and Repair

Pistons And Connecting Rods, Removing And Installing





1 - Piston ring
- Offset gaps by 12O°
- Remove and install with piston ring pliers.
- "Top" marking faces toward piston crown
- Ring gap, checking see Fig. 1
- Ring to groove clearance, checking see Fig. 2

2 - Piston
- Checking see Fig.3
- Mark installation position on connecting rod and cylinder number.
- High point of piston crown faces toward center of cylinder block.
- Install with piston tool 3278 Fig.5

3 - Connecting rod
- Always replace as a set.
- Mark cylinder number -B-
- Installation position: marks -A- must be on top of each other.

4 - Connecting rod bearing cap
- Note installation position

5 - 30 Nm (22 ft lb) and turn 1/4 turn (90°) further.
- Replace.
- Oil contact surfaces and threads.
- To measure radial clearance tighten to 3O Nm (22 ft lb) but not further.

6 - Bearing shell
- Note installation position
- Do not mix up used be bearing shells.
- The lugs of the bearing shells must fit tightly into the recesses.
- Check radial clearance with Plastigage�:
new: 0.02.to 0.07 mm
wear limit: 0.1O mm

NOTE: When checking clearance do not turn crankshaft

7 - Cylinder block
- Cylinder bores, checking Fig. 1
- Piston and cylinder dimensions see below.

8 - Piston pin
- If difficult to remove, heat piston to 60° C (140° F).
- Remove and install with VW 222A.

9 - Circlip

Piston Ring Gap, Checking.

Fig. 1:

- Push ring squarely from above down to approximately 15 mm from bottom end of cylinder. To push down, use a piston without rings.

Ring To Groove Clearance, Checking

Fig. 2:

- Clean groove before checking.

Piston, Checking

Fig. 3:

- Measure pistons approx. 6 mm from the lower edge of the skirt1 at 90° to the piston pin axis.

Deviation from nominal dimension: Max. 0.04 mm

Cylinder Bores, Checking

Fig. 4:

- Measure bores at 3 locations in both directions -A- across the engine and -B- in line with crankshaft.

- Use inside dial gauge 50 to 100 mm

- Deviation from nominal dimension max. 0.08 mm.

CAUTION: Do not measure cylinder bores when the cylinder block is mounted in a repair stand or adapter bracket 3269 as incorrect measurements would be possible.

Piston, Installing With Piston Tool 3278

Flg. 5:

CAUTION: If you use a new tool to install the pistons, first pass piston with oiled piston rings twice through the tool and then remove any metal shavings. Only then install pistons with rings.

- Oil tool and push piston in. High point of piston crown must face toward the lug on the tool (arrow).

- Hold tool with installed piston by the rim and push piston in using both thumbs.

- Push piston in until it protrudes approx. 15 mm from the lower edge of the tool.

- Place piston in appropriate cylinder bore. The lug on tool (arrow) must face toward the center of the cylinder block.

- Hold tool tightly against cylinder block and push piston in.

Piston And Cylinder Dimensions