Piston and Connecting Rod Assembly Overview

Piston and Connecting Rod Assembly Overview





1 Bolt, 30 Nm + 90° (1/4 additional turn)

• Replace

• Lubricate the threads and contact surfaces.

• Tighten to 30 Nm to measure radial play, do not turn further.

2 Pressure Relief Valve, 27 Nm

• Opening pressure 1.3 to 1.6 bar pressure.

3 Oil Spray Jet

• For piston cooling.

4 Connecting Rod Bearing Cap

• Note the installed position.

• Due to the way the separated connecting rod breaks (cracks), the cap fits only in one position and only onto the respective connecting rod.

• Affiliation to the cylinder mark - B -.

• Installed position: Marks - A - point to the belt pulley side.

5 Bearing Shell

• Note the installed position, refer to => [ Bearing Shells, Installed Location ].

• Do not interchange used bearing shells.

• Axial play new: 0.10 to 0.35 millimeter (mm).

Wear limit: 0.4 mm

• Measure radial clearance with Plastigage(R):

New: 0.02 to 0.06 mm

Wear limit: 0.09 mm

Do not turn the crankshaft when measuring radial play.

6 Connecting Rod

• With a cracked bearing cap.

• Separate new connecting rods. Refer to => [ New Connecting Rod, Separating ] Procedures.

• Only replace as a set.

• Affiliation to the cylinder mark - B -.

• Installed position: Marks - A - point to belt pulley side.

7 Circlip

8 Piston Pin

• If difficult to move, heat the piston to 60 °C (140 °F).

• Remove and install using pilot drift (VW 222A).

9 Piston

• Checking, refer to => [ Pistons, Checking ] Testing and Inspection.

• Mark the installed position and cylinder allocation.

• Arrow on piston face points toward the belt pulley side.

• Install with a piston ring compressor.

• Checking cylinder bore, refer to => [ Cylinder Bore, Checking ] Testing and Inspection.

• Piston and cylinder dimensions. Refer to => [ Piston and Cylinder Dimensions ] Piston and Cylinder Dimensions.

10 Piston Rings

• Offset gaps by 120°

• Use piston ring pliers for removal and installation.

• Marks face toward the piston crown.

• Checking ring gap, refer to => [ Piston Ring Gap, Checking ] Testing and Inspection.

• Checking piston ring groove clearance, refer to => [ Piston Ring Groove Clearance, Checking ] Testing and Inspection.

Bearing Shells, Installed Location





Bearing shell - 1 - with oil bore - arrow - for connecting rod.

Bearing shell - 2 - without oil bore for connecting rod cover.

- Place the bearing shells centrally into the connecting rod and connecting rod cap.

Dimension - a - must be the same at left and right.