Connecting Rod: Service and Repair

Pistons and Connecting Rod Assembly Overview





1 Bolts

• Replace

• Lubricate the threads and contact surface

• 30 Nm plus an additional 90° turn

2 Connecting Rod Bearing Cap

• Mark for re-installation

• Mark allocation to cylinder with paint - B

• When installing bearing cap, observe: The wide thrust flange - A - must point to the same side on connecting rod and connecting rod bearing cap

3 Bearing Shell

• Check that retaining tabs are secured

• Mark used bearing shells for reinstallation but not on the running surface

• Replace bearing shells that have worn down to the base layer

4 Connecting Rod

• Only replace as set

• Mark allocation to cylinder with paint - B.

• When installing bearing cap, observe: The wide thrust flange - A - must point to the same side on connecting rod and connecting rod bearing cap

• Radial clearance, measuring, refer to => [ Connecting Rod, Measuring Radial Clearance ] Connecting Rod, Measuring Radial Clearance

5 Piston Pin

• If tight, heat piston to 60 °C / 140 °F

• Removing and installing using a Drift (VW 222 A)

6 Circlip

• Replace

7 Piston

• Mark the installation position and cylinder allocation.

• Arrow on piston face points toward belt pulley side

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

• Replace the piston if there are cracks on the piston head or piston shaft

• Install with piston ring compressor

• Piston and cylinder dimensions, refer to => [ Piston and Cylinder Dimensions ] [1][2]Piston, Engine

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

8 Piston Rings

• Offset gaps by 120°

• Use piston ring pliers for removal and installation

• "TOP" marking or inscribed side must point to piston head

• 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

Installed Position of Piston and Piston to Cylinder Allocation





CAUTION!
The coating on the piston crown could be destroyed.

• Mark the allocation to the cylinder on the piston crown with paint for installation. Do not mark the piston crown with a punch, notch or similar object.

Installation position:

• The arrows on the piston heads point to the belt pulley side.

Mark Connecting Rod





• Only replace the connecting rods as a set.

- Mark the connecting rod and connector rod bearing caps to each other and to the cylinder - arrow - with paint for installation.

Connecting Rod, Installed Location





• The molded tabs - arrows - on the beveled surfaces of the connecting rod pairs "1 and 2", "3 and 4" and "5 and 6" must face each other.

Oil Spray Jet for Piston Cooling





1. Insert the bolt with locking compound and tighten to 9 Nm; locking compound.

2. Oil spray jet with spray nozzle valve (opening pressure 2 to 2.4 bar)

• Do not bend the oil spray nozzles.

• Replace the oil spry nozzles if they are bent.