Pistons and Connecting Rod Overview

Pistons and Connecting Rod Overview

• Lubricate all bearings and running surfaces.

• Oil spray nozzle and pressure relief valve, refer to => [ Oil Spray Jet and Pressure Relief Valve ].






1 Bolts

• Replace

• 45 Nm plus an additional 90° turn

• Lubricate threads and contact surface

• Use old bolts for radial play measurement, tighten to 45 Nm but do not tighten further

2 Connecting Rod Bearing Cap

• Mark allocation to cylinder with paint - B -

• Installed position: Markings - A - face the pulley side

3 Bearing Shells

• Upper bearing shell with oil bore for piston pin lubrication

• Installed position, refer to => [ Bearing Shell Installation Position
in the Connecting Rods ]

• Mark used bearing shells for reinstallation but not on the running surface

• Replace bearing shells that have worn down to the nickel layer

4 Connecting Rod

• With oil bore for piston pin lubrication

• Only replace as set

• Mark allocation to cylinder with paint - B -

• Installed position: Markings - A - face the pulley side

• Measuring axial play, refer to => [ Connecting Rod, Measuring Axial Clearance ] Connecting Rod, Measuring Axial Clearance

• Radial clearance, measuring, refer to => [ Connecting Rod, Measuring Radial Clearance ] Connecting Rod, Measuring Radial Clearance

5 Locking Ring

• Replace

6 Piston Pin

• Heat piston to 60 °C (140 °F) if it is difficult to move.

• Removing and installing using a pilot drift (VW 222 A)

7 Piston

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

• Mark installed location to connecting rod and affiliation to cylinder

• Installed position: Arrow on the piston face points toward the belt pulley side

• Install with piston ring compressor

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

8 Piston Rings

• Offset gaps by 120°

• Use piston ring pliers for removing and installing

• "TOP" faces toward piston crown

• Checking ring gap, refer to => [ Piston Ring Gap, Checking ] Piston, Pistons Rings and Cylinder Bore, Checking

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

Bearing Shell Installation Position in the Connecting Rods





- Install the bearing shell in the center of the connecting rod or in the connecting rod cover.

• Dimension - a - = approximately 1.5 mm.

Oil Spray Jet and Pressure Relief Valve





1. Bolt with pressure relief valve - 27 Nm

2. Oil spray jet (for piston cooling)


• Installed position: Align the guiding edge of the oil spray jet to the machined surface of the cylinder block.

• Do not bend the oil spray nozzles.

• Replace the oil spry nozzles if they are bent.