Piston and Connecting Rod Assembly Overview

Piston and Connecting Rod Assembly Overview





1 Piston rings

• Offset gaps by 120 degrees.

• Use piston ring pliers for removal and installation.

• "TOP" faces toward piston crown.

• Checking ring gap, refer to --> [ Piston Ring Gap, Checking ] Piston Ring Gap, Checking/

• Check piston ring groove clearance, refer to --> [ Piston Ring Groove Clearance, Checking ] Piston Ring Groove Clearance, Checking.

2 Piston

• Checking, refer to --> [ Pistons, Checking ] Testing and Inspection.

• Mark installed location to connecting rod and affiliation to cylinder.

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

• Installing piston, refer to --> [ Piston, Installing ] Piston, Installing.

3 Circlip

• Ensure seated tightly.

4 Connecting rod

• Only replace as set.

• Affiliation to the cylinder mark - B -.

• Installation position: Markings - A - must align.

5 Bearing shell

• Note installation position.

• Do not interchange used bearing shells.

• 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 with Plastigage: New: 0.02 to 0.07 mm Wear limit: 0.10 mm. Do not turn crankshaft when checking radial clearance.

6 Connecting rod bearing cap

• Affiliation to the cylinder mark - B -.

• Installation position: Markings - A - must align.

7 30 Nm + 1/4 turn (90°)

• Replace.

• Lubricate threads and contact surface.

• Tighten to 30 Nm to measure radial play, do not turn further.

8 Cylinder block

• Cylinder bore checking, refer to --> [ Cylinder Bore, Checking ] Testing and Inspection.

• Removing and installing crankshaft, refer to --> [ Crankshaft Assembly 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 piston to 60 °C.

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