Cylinder Block Assembly: Locations
Piston and connecting rod, assembly overview
Note: From model year 1998, industrially cracked connecting rods (serrated separation surfaces) were installed.
Standard connecting rods
1 - Circlip
2 - Piston pin
^ If difficult to move, heat piston to 60°C
3 - Piston
^ Checking
^ Mark installed position and cylinder allocation
^ Arrow on piston face points toward belt pulley side
^ Install with piston ring compressor
^ Cylinder bore, checking
4 - Piston rings
^ Offset gaps by 120°
^ Use piston ring pliers for removal and installation
^ "TOP" faces toward piston crown
^ Checking ring gap
^ Check piston ring groove clearance
5 - Connecting rod
^ Only replace as a set
^ Mark affiliation to cylinder - A -
^ Installed location:
- Markings - B - face: Cyl. 1 to 3 to belt pulley side Cyl. 4 to 6 to flywheel side
6 - Connecting rod bearing cap
^ Note installation position
7 - Connecting rod bolt, 30 Nm plus 1/4 turn (90°)
^ Replace
^ Lubricate threads and contact surface
^ Tighten to 20 Nm to measure radial play, do not turn further
8 - Bearing shell
^ Note installation position
^ Do not interchange used bearing shells
^ Measure radial play with Plastigage,
- New: 0.015 to 0.062 mm; Wear limit: 0.120 mm; Do not turn crankshaft when checking radial clearance
Cracked connecting rods (serrated separation surface)
1 - Connecting rod bolt
^ M8: 30 Nm plus 1/4 turn (90°)
^ M8.5: 40 Nm plus 1/4 turn (90°)
^ Replace
^ Lubricate threads and contact surface
^ Tighten to 30 Nm to measure radial play, do not turn further
2 - Connecting rod bearing cap
^ Mark affiliation to cylinder - A -
^ Installed location:
- Markings - B - face: Cyl. 1 to 3 to belt pulley side Cyl. 4 to 6 to flywheel side
3 - Bearing shell
^ Note installation position
^ Do not interchange used bearing shells
^ Measure radial play with Plastigage,
- New: 0.015 to 0.062 mm; Wear limit: 0.120 mm; Do not turn crankshaft when checking radial clearance
4 - Connecting rod
^ Only replace as set
^ Mark affiliation to cylinder - A -
^ Installed location:
- Markings - B - face: Cyl. 1 to 3 to belt pulley side Cyl. 4 to 6 to flywheel side
5 - Circlip
6 - Piston pin
^ If difficult to move, heat piston to 60°C
7 - Piston
^ Mark installed position and cylinder allocation
^ Arrow on piston face points toward belt pulley side
^ Install with piston ring compressor
^ Checking
^ Cylinder bore, checking
8 - Piston rings
^ Offset gaps by 120°
^ Use piston ring pliers for removal and installation
^ "TOP" faces toward piston crown
^ Checking ring gap
^ Check piston ring groove clearance
From model year 1998, cracked connecting rods (serrated separation surfaces) are installed
Distinguishing feature:
A - standard connecting rods (smooth separation surface)
B - cracked connecting rods (rough separation surface)
Checking piston ring gap
Special tools, testers and auxiliary items required
^ Feeler gauge
- Insert ring into lower cylinder bore at a right angle from above, to approx. 15 mm from cylinder edge.
Checking ring to groove clearance
Special tools, testers and auxiliary items required
^ Feeler gauge
- Clean ring groove before checking.
Checking piston
Special tools, testers and auxiliary items required
^ External micrometer 75 to 100 mm
- Measure pistons approx. 10 mm from bottom edge and at points offset by 90° to piston pin axis.
- Deviation from nominal dimension: max. 0.04 mm
Checking cylinder bores
Special tools, testers and auxiliary items required
^ Internal dial gauge 50 to 100 mm
Work sequence
- Measure bores at 3 locations in both directions - A - across engine and - B - in line with crankshaft.
- Deviations from nominal dimension: max. 0.08 mm
Note: Measurement of the cylinder bore may not be performed when the cylinder block is mounted on engine and transmission holder VAS 6095 or holding fixture VW 540 as false measurements will result.