Pistons and Connecting Rod Overview

Pistons and Connecting Rod Overview






1 Piston Rings

• Offset gaps by 120°.

• Use piston ring pliers for removing and installing.

• "TOP" faces toward the piston crown.

• Ring gap checking, refer to => [ Piston Ring Gap, Checking ] Piston Ring Gap, Checking.

• Piston ring groove clearance checking, refer to => [ Piston Ring Groove Clearance, Checking ] Piston Ring Groove Clearance, Checking.

2 Piston

• Checking, refer to => [ Piston, Checking ] Piston, Checking.

• Mark the installed location to the connecting rod and affiliation to which cylinder it belongs to.

• The two deep valve recesses in the piston head point toward the center of the cylinder block.

• Installing, refer to => [ Piston, Installing ] Piston, Installing.

3 Circlip

• Make sure it is tight.

4 Connecting Rod

• Only replace as a set.

• Affiliation to the cylinder mark - B -.

• Installed position: Marks - A - must align.

5 Bearing Shell

• Note the installed position.

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

• Bearing shell retaining tabs must be firmly seated in the notches.

• Axial play:

New: 0.05 to 0.31 mm

Wear limit: 0.40 mm

• Measure radial clearance using Plastigage(R):

New: 0.02 to 0.07 mm

Wear limit: 0.10 mm

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

6 Connecting Rod Bearing Cap

• Affiliation to the cylinder mark - B -.

• Installed position: Marks - A - must align.

7 Bolt

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

• Always replace.

• Lubricate the threads and contact surface.

• Tighten to 40 Nm to measure the radial play, do not tighten ti additional angle.

8 Cylinder Block

• Cylinder bore checking, refer to => [ Cylinder Bore, Checking ] Cylinder Bore, Checking.

• Crankshaft overview, refer to => [ Crankshaft Overview ] Service and Repair

• Piston and cylinder dimensions, refer to => [ Piston and Cylinder Dimensions ] Piston and Cylinder Dimensions.

9 Piston Pin

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

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