Overview - Piston And Connecting Rod

Fig 1: Identifying Piston And Connecting Rod Overview

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

1. Bolts
   • 30 Nm +90° turn
   • Lubricate the thread and contact surface.
   • Replace after removing
2. Connecting Rod Bearing Cap
   • Pay attention to the installed position.
   • Due to the separation procedure (cracking) of the connecting rod, the connecting rod bearing cap only fits in one position and only to the corresponding connecting rod.
   • Use color to identify the cylinder and connecting rod to which it belongs -B-.
   • Installed position: Markings -A- point to belt pulley side
3. Bearing Shells
   • Installed position, refer to Fig 3
   • Replace any worn bearing shells
   • Note the version: the upper bearing shell (to piston) is made of wear-resistant material. How to recognize new bearing shells: there is a black line on the contact surface near the separating point.
   • Make sure it is secure
4. Connecting Rod
   • With a cracked connecting rod bearing cap
   • Always replace as a set.
   • Use color to identify the cylinder and connecting rod bearing cap to which it belongs -B-.
   • Axial clearance: Wear limit: 0.37 mm
   • Radial play, measuring, refer to CONNECTING RODS, CHECKING RADIAL CLEARANCE .
   • New connecting rod, separating, refer to Fig 4.
   • Installed position: Markings -A- face the pulley side
5. Locking Ring
   • Quantity: 2
   • Replace after removing
6. Piston Pin
   • Removing and installing, refer to PISTONS .
7. Piston
   • with the combustion chamber
   • Replace the piston if there are cracks on the piston head or piston shaft
   • Mark the installation position and cylinder allocation, refer to Fig 2
   • Removing and installing, refer to PISTONS .
   • Check piston and cylinder bore, refer to PISTONS AND CYLINDER BORE, CHECKING .
   • Measure the piston projection at "TDC", refer to PISTON PROJECTION, MEASURING AT TDC .
8. Compression rings
   • Measuring the gap, refer to Figure
   • Measuring side clearance, refer to Figure
   • Use piston ring pliers (commercially available) for removing and installing
   • Installed position: The "TOP" marking or side with writing faces the piston crown.
   • Offset gaps by 120°
9. Oil Scraping Ring
   • Measuring the gap, refer to Figure
   • Measuring side clearance, refer to Figure
   • Use piston ring pliers for removing and installing
   • Installed position: The "TOP" marking or side with writing faces the piston crown.
   • Offset gaps by 120° on the lower compression ring

Fig 2: Identifying Piston Installed Location And Allocation, Piston To Cylinder

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

• Arrow on the piston crown facing the pulley side -arrow-.

Fig 3: Identifying Installation Position Of Bearing Shells

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Install the bearing shells into the center of the connecting rod and into the connecting rod bearing cap.

• Dimension -a- = 2.5 mm (0.098 inch).

Fig 4: Clamping Connecting Rod In Vise Equipped With Aluminum Protective Pads

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

The rod and caps on new connecting rods may become strongly stuck together. If the connecting rod bearing cap cannot be removed by hand, proceed as follows:

-- Clamp the connecting rod in a vise, which has protectors over the grips to prevent damage.

• Clamp the connecting rod below the dotted line.

-- Remove the screws -arrows- approximately five turns.

-- Carefully tap the connecting rod bearing cap with a plastic hammer in direction of -arrow- until it comes loose.

Fig 5: Carefully Taping Against Connecting Rod Bearing Cap

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Fig 6: Identifying Oil Spray Jet And Pressure Relief Valve

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

1. Bolt with Pressure Relief Valve - 27 Nm
2. Piston cooling oil spray jet

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