Piston and Connecting Rod Overview

Piston and Connecting Rod Overview






1 Bolt

• 45 Nm + an additional 90° (1/4) turn.

• Always replace.

• Lubricate the threads and contact surface.

• Use the old bolts to measure the radial play.

• Do not tighten the additional 90° (1/4) turn when measuring the radial play.

2 Connecting Rod Bearing Cap

• Pay attention to the installed position.

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

• Mark the affiliation to the cylinder - A -.

• Installed position: The marks - B - point to the belt pulley side.

3 Bearing Shell

• Installed position, refer to => [ Installed Position of the Bearing Shell ].

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

• Axial play:

New: 0.10 to 0.35 mm

Wear limit: 0.40 mm

• Measure the radial clearance using Plastigage(R):

New: 0.02 to 0.06 mm

Wear limit: 0.09 mm

• Do not rotate the crankshaft when measuring the radial clearance.

4 Pressure Relief Valve

• 27 Nm

• Opening pressure 1.6 to 1.9 bar

5 Oil Spray Jet

• For piston cooling.

6 Lock Ring

7 Piston Pin

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

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

8 Piston

• Removing and installing, refer to => [ Piston ] 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.

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

9 Compression Rings

• Offset the gaps by 120°.

• Use piston ring pliers for removal and installation.

• "TOP" or the manufacturer identification must face the piston crown.

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

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

10 Oil Scraping Ring

• 2 piece

• Install the upper steel ring so the gap is offset by 120° to the neighboring compression ring.

• Offset all oil scraping ring component gaps to each other.

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

• The side clearance cannot be measured.

11 Connecting Rod

• Always replace as a set.

• Mark the affiliation to the cylinder - A -.

• Installed position: The marks - B - point to the belt pulley side.

Installed Position of the Bearing Shell





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

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