Pistons and Connecting Rod Assembly Overview

Pistons and Connecting Rod Assembly Overview





1 Connecting rod bolt, 40 Nm plus an additional 120° turn

• Replace

• Lubricate the threads and contact surface

2 Connecting rod bearing cap

• Do not interchange

• 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

• 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 ] Removal and Replacement

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 ] Removal and Replacement

5 Piston pin

• If tight, heat piston to 60 °C

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

6 Circlip

• Replace

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





- Identify allocation to cylinder with paint on piston crown.

• Do not use a center punch or scribe, since the piston head coating will be damaged.

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.

• Do not interchange connecting rod bearings.

- Before removing, mark allocation of connecting rod and connecting rod bearing caps to each other and to cylinder with paint - arrow -.

Connecting Rod, Installed Location





• Molded tabs - arrows - at the beveled surfaces of the connecting rod pairs 1 and 2, 3 and 4, 5 and 6 as well as 7 and 8 must point toward each other.

Oil Spray Jet For Piston Cooling





1. Oil spray jet

2. Bolts - 9 Nm. Insert with locking compound; Locking compound.

CAUTION!
• Do not bend the oil injector jets.

• Bent oil injector jets must be replaced.