Pistons and Connecting Rod Assembly Overview

Pistons and Connecting Rod Assembly Overview





1 Bolt

• Replace

• 30 Nm + 90° (1/4) additional turn.

• Lubricate the threads and contact surface.

• 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 separation procedure (cracking) for the connecting rod, the bearing cap only fits in one position and only on the appropriate connecting rod.

• Affiliation to the cylinder mark - B -.

• Installed position: marks - A - face the pulley side.

5 Bearing Shell

• Note the installed position, refer to.

• Do not interchange used bearing shells.

• Axial play new: 0.10 to 0.35 mm.

Wear limit: 0.4 mm.

• Measure radial clearance with Plastigage:

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 cracked bearing cap.

• Separating 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 - face the pulley side.

7 Circlip

8 Piston Pin

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

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

9 Piston

• Checking, refer to => [ Pistons, Checking ] Piston, Rings and Cylinder Bore, Checking.

• 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 ] Piston, Rings and Cylinder Bore, Checking.

• 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 ] Piston, Rings and Cylinder Bore, Checking.

• Checking piston ring groove clearance, refer to => [ Piston Ring Groove
Clearance, Checking ] Piston, Rings and Cylinder Bore, Checking.

Bearing Shell, Installed Position





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

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

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

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