Pistons and Connecting Rod Assembly Overview

Pistons and Connecting Rod Assembly Overview





1 Bolts

• Replace

• Lubricate threads and contact surface

• 40 Nm plus an additional 120° turn

2 Connecting rod bearing cap

• Mark for re-installation

• Mark affiliation to cylinder with paint, refer to => [ Mark Connecting Rod ]

• Installation position of connecting rod pairs, refer to => [ Connecting Rod, Installed Location ]

3 Bearing shells

• Check that retaining tabs are secured

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

• Replace the bearing shells worn down to the base layer

• Over-sized bearings are available for reworked crankshaft connecting rod journals.

• Insert bearing shells with correct color marking, refer to => [ Connecting Rod, Allocating with Connecting Rod Bearing Shells to crankshaft ] Connecting Rod, Allocating With Connecting Rod Bearing Shells to Crankshaft

4 Connecting rod

• Only replace as set

• Mark affiliation to cylinder with paint, refer to => [ Mark Connecting Rod ]

• Installation position of connecting rod pairs, refer to => [ Connecting Rod, Installed Location ]

• Axial play for each new connecting rod pair: 0.20 to 0.27 mm

• Axial play wear limit: 0.30 mm

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

• Insert connecting rod with correct identification letter, refer to => [ Connecting Rod, Allocating with Connecting Rod Bearing Shells to crankshaft ] Connecting Rod, Allocating With Connecting Rod Bearing Shells to Crankshaft

5 Piston pin

• If tight, heat piston to 60 °C

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

6 Circlip

7 Piston

• Installation position of pistons, refer to => [ Piston Installation Position ]

• Piston and cylinder dimension, piston allocation to cylinder bore, refer to => [ Piston and Cylinder Dimensions ] [1][2]Piston, Engine

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

• Install with piston ring compressor

• Measuring cylinder bore, refer to => [ Cylinder Bore, Measuring ] 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

• Gap, measuring, refer to => [ Piston Ring End Gap, Measuring ] Piston Ring End Gap, Measuring

• Measuring side clearance, refer to => [ Piston Ring Side Clearance, Measuring ] Piston Ring Side Clearance, Measuring

Piston Installation Position





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:

• Arrows on piston heads point to belt pulley side.

• Large valve recesses - 1 - point toward center of engine.

Mark Connecting Rod





• Only replace connecting rod 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 connecting rod pairs "1 and 2", "3 and 4", " 5 and 6" and "7 and 8" must face each other.

Oil Spray Jet for Piston Cooling





1. Oil spray jet

2. Insert the bolt with locking compound. Tighten to 9 Nm.

• Do not bend the oil injector jets.

• Bent oil injector jets must be replaced.