Piston And Connecting Rod Overview

Fig 1: Identifying Piston And Connecting Rod Assembly Overview

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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.
3. Oil Spray Jet 
   • For the piston cooling.
4. Connecting Rod Cap 
   • Pay attention to 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: The marks -A- point to belt pulley side.
5. Bearing Shell 
   • Note the installed position, refer to Fig 2.
   • Do not interchange used bearing shells (mark them).
   • Axial play new: 0.10 to 0.35 mm.

     Wear limit: 0.4 mm.

   • Measure the radial clearance using Plastigage:

     New: 0.02 to 0.06 mm.

     Wear limit: 0.09 mm.

     Do not rotate the crankshaft when measuring the radial play.

6. Connecting Rod 
   • With a cracked bearing cap.
   • Separating a new connecting rod. refer to NEW CONNECTING ROD, SEPARATING .
   • Only replace as a set.
   • Affiliation to the cylinder mark -B-.
   • Installed position: The 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 a pilot drift VW 222 A.
9. Piston 
   • Checking, refer to Figure.
   • Mark the installed position and the 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 Figure.
   • For the correct piston and cylinder dimensions, refer to 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.
    • Ring gap, checking. Refer to Figure.
    • Piston ring groove clearance, checking. Refer to Figure.

Fig 2: Identifying Bearing Shells - Installed Positions

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

The bearing shell -1- with a oil bore -arrow- is for the connecting rod.

The bearing shell -2- without a oil bore is for the connecting rod cap.

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

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