Pistons And Connecting Rod Overview

Fig 1: Piston And Connecting Rod, Assembly Overview

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

1. Bolt
   • 30 Nm + an additional 90° (1/4) turn.
   • Always replace.
   • Lubricate the threads and contact surface.
   • Tighten to 30 Nm to measure radial play, do not tighten the additional 90° 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 Bearing Cap
   • Pay attention to the installed position.
   • Due to the separation procedure (cracking) for the connecting rod, the connecting rod bearing cap only fits in one position and only on the appropriate connecting rod.
   • Mark which cylinder the cap belongs to.
   • Installed position: the marks -A- point to the 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 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 new connecting rods. Refer to NEW CONNECTING ROD, SEPARATING .
   • Always replace as a set.
   • Mark which cylinder the connecting rod belongs to.
   • Installed position: The 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 a pilot drift VW 222 A.
9. Piston
   • Checking, refer to Figure.
   • 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.
   • Piston and cylinder bore, checking. Refer to PISTONS AND CYLINDER BORE, CHECKING .
10. Piston Rings
    • Offset gaps by 120°.
    • Use piston ring pliers for removal and installation.
    • Marks face toward the piston crown.
    • Checking the ring gap. Refer to Figure.
    • Checking the piston ring groove clearance. Refer to Figure.

Fig 2: Bearing Shells - Installed Positions

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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

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

-- 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.