Connecting Rod: Service and Repair

Pistons and Connecting Rod Assembly Overview

CAUTION!
The crankshaft, pistons, and connecting rods must not be replaced! Only removal and installation of these components is permitted.





1 Bolt, connecting rod, 30 Nm + 1/4 turn (90°)

• Replace.

• Lubricate threads and contact surface.

• Use old bolt to measure radial play.

2 Connecting rod bearing cap

• Note installation position.

3 Bearing shell

• Note installation position.

• Note version: Upper bearing shell (to piston) made of wear-resistant material, identification: Black line on contact surface in area of separating point.

• Do not interchange used bearing shells.

• Insert bearing shells in center.

• Ensure seated tightly.

• Axial play wear limit: 0.37 mm.

• Measure radial clearance with Plastigage: Wear limit: 0.08 mm. Do not turn crankshaft when checking radial clearance.

4 Connecting rod

• Mark matching cylinder - arrow A -.

• Installation position: Markings - arrows B - point to vibration damper side.

5 Circlip

6 Piston

• With combustion chamber.

• Mark installed position and cylinder allocation.

• Installed position and allocation, piston/cylinder, refer to --> [ Piston: Installed position and allocation, piston/cylinder ] Piston Rings, Cylinder Bores and Piston Checking.

• Directional arrow on piston head points to intake side.

• Install with piston ring compressor.

• Checking piston position at Top Dead Center (TDC), refer to --> [ Piston Position, Checking at TDC ] Piston Position, Checking at TDC.

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

• Cylinder bore checking, refer to --> [ Cylinder Bore, Checking ] Piston Rings, Cylinder Bores and Piston Checking

7 Piston pin

• If difficult to move, heat piston to 60 °C.

• Removing and installing using a drift (VW 222 A).

8 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 Rings, Cylinder Bores and Piston Checking

• Check piston ring groove clearance, refer to --> [ Piston Ring Groove Clearance, Checking ] Piston Rings, Cylinder Bores and Piston Checking