Pistons and Connecting Rod Assembly Overview

Pistons 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 => [ Piston Ring Gap, Checking ] Piston Ring Gap, Checking.

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

2 Piston

• With combustion chamber

• Mark installed position and cylinder allocation

• Installed position and allocation, piston/cylinder => [ Installed Position of Piston and Piston/Cylinder Allocation ] Installed Position of Piston and Piston/Cylinder Allocation.

• Arrow on piston face points toward belt pulley side

• Install with piston ring compressor

• Replace if piston skirt is cracked

• Checking piston position at TDC => [ Piston Position at TDC, Checking ] Piston Position at TDC, Checking.

3 Piston pin

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

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

4 Circlip

5 Connecting rod

• Mark matching cylinder with colored marker - arrows A -

• Installation position: Markings - arrows B - point to belt pulley side

• With cracked bearing cap

• Separate new connecting rod => [ New Connecting Rod, Separating ] Service and Repair.

6 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

7 Cylinder block

• Cylinder bore, checking => [ Cylinder Bore, Checking ] Cylinder Bore, Checking.

• Piston and cylinder dimensions => [ Piston and Cylinder Dimensions ] [1][2]Specifications.

8 Connecting rod bearing cap

• Note installation position

• Due to the separation procedure (cracking) of the connecting rod, the cap only fits in one position and only to the corresponding connecting rod.

9 Oil spray jet

• For piston cooling

• When replacing the oil injector jet, pay attention to the correct allocation for the pistons

10 25 Nm

• Install without sealant

11 Connecting rod bolt 30 Nm + 90° (1/4 additional turn)

• Replace

• Lubricate threads and contact surface

• Use old bolt to measure radial play