Pistons and Connecting Rod Overview

Pistons and Connecting Rod Overview






1 Bolt

• 30 Nm + 90° (1/4) additional turn.

• Always replace.

• Lubricate the threads and contact surface.

• Tighten to 30 Nm to measure the radial play, do not tighten the additional turn.

2 Pressure Relief Valve

• 27 Nm

• Opening pressure: 1.3 to 1.6 bar excess pressure.

3 Oil Spray Jet

• For piston cooling.

4 Connecting Rod Cap

• Pay attention to the installed position.

• Due to the separation procedure (cracking) of the connecting rod, the cap only fits in one position and only to the corresponding connecting rod.

• Mark which cylinder the connecting rod/cap belongs - B -

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

5 Bearing Shell

• Pay attention to the installed position.

• Do not interchange used bearing shells (mark them).

• Axial play new: 0.10 to 0.35 mm.

Wear limit: 0.4 mm.

• Measure radial clearance using Plastigage:

New: 0.02 to 0.06 mm.

Wear limit: 0.09 mm.

Do not rotate the crankshaft when measuring radial play.

6 Connecting Rod

• With a cracked bearing cap.

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

• Only replace as a set.

• Mark which cylinder the connecting rod belongs - B -.

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

7 Circlip

8 Piston Pin

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

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

9 Piston

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

• Mark the installed position and cylinder allocation.

• The arrow on the piston face points toward the belt pulley side.

• Install using a piston ring compressor.

• Cylinder bore, checking. Refer to => [ Cylinder Bore, Checking ] Testing and Inspection.

10 Piston Rings

• Offset gaps by 120°.

• Use piston ring pliers for removal and installation.

• The marks face toward the piston crown.

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

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

Bearing Shell, Installed Position





Bearing shell - 1 - with a oil bore - arrow -.

Bearing shell - 2 - without a oil bore.

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

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