Pistons and connecting rods, disassembling and assembling: Notes

Fig 1: Pistons And Connecting Rods, Disassembling And Assembling Overview

Courtesy of VOLKSWAGEN UNITED STATES, INC.

1 - 30 Nm + 1/4 turn (90 ° ) further

• Oil threads and contact surface
• To measure radial clearance, tighten to 30 Nm but not further

2 - Pressure relief valve, 27 Nm

• Opens at: 2.5...3.2 bar

3 - Oil spray jet

• For piston cooling

4 - Connecting rod bearing cap

• Mark cylinder number - B  -
• Installed position: Marking - A  - must face toward pulley end

5 - Bearing shell

• Note installed position
• Do not interchange used bearing shells (mark)
• Make sure that bearing shell is seated correctly in retaining lugs
• Axial clearance, New: 0.10...0.35 mm; Wear limit: 0.40 mm

• Check radial clearance with Plastigage™, New: 0.01...0.05 mm; Wear limit: 0.12 mm
• Do not rotate crankshaft when checking radial clearance

6 - Cylinder block

• Checking cylinder bore Checking cylinder bore 
• Piston and cylinder dimensions → Piston and cylinder dimensions 

7 - Bearing shell

• With oil drilling for piston pin lubrication
• Note installed position
• Do not interchange used bearing shells (mark)
• Axial clearance, New 0.10...0.35 mm; Wear limit: 0.40 mm

• Check radial clearance with Plastigage™, New: 0.01...0.05 mm; Wear limit: 0.12 mm
• Do not rotate crankshaft when checking radial clearance

8 - Connecting rod

• Only replace as set
• Mark cylinder number - B  -
• Installed position: Marking - A  - must face toward pulley end
• With oil drilling for piston pin lubrication

9 - Circlip

10 - Piston pin

• If difficult to move, heat piston to approx. 60 °C
• Remove and install with VW222a

11 - Piston rings

• Offset gaps by 120 °
• Remove and install with piston ring pliers
• "TOP" must face toward piston crown
• Checking ring gap Checking piston ring gap 

• Checking ring to groove clearance Checking ring to groove clearance 

12 - Piston

• Checking Checking piston 
• Mark installed position and cylinder number
• Arrow on piston crown must point to pulley end
• Install using piston ring clamp

13 - Connecting rod bolt

• Replace