Connecting Rod: Locations
Assembly overview
Gradual introduction of industrially cracked connecting rods
Piston with conventional connecting rod
Piston with industrially cracked connecting rod
Gradual introduction of industrially cracked connecting rods
Identification:
A - conventional connecting rods with polished parting surfaces
B - industrially cracked connecting rods with rough parting surfaces
Piston with conventional connecting rod
Piston with industrially cracked connecting rod
Piston with conventional connecting rod
Note:
^ When working on the engine, it should be secured with the Holding fixture VW540 and the Spacers VW 540/1 B to the support clamp.
1 - Piston rings
^ Gaps offset by 120°
^ Remove and install using piston ring pliers
^ "TOP" faces piston crown
2 - Piston
^ Mark installation position and cylinder number
^ Arrow on piston crown points to belt pulley end Install using piston ring clamp
3 - Connecting rod
^ Replace as set only
^ Mark cylinder number - B -
^ Installation position: Marking - A - faces belt pulley end
4 - Connecting rod bearing cap
^ Mark cylinder number - B -
^ Installation position: Marking - A - faces belt pulley end
5 - 30 Nm plus 1/4 turn (90°)
^ Replace
^ Oil threads and contact surfaces
^ To measure radial clearance, tighten to 30 Nm, but do not turn further
6 - Pressure relieve valve, 27 Nm
7 - Oil spray jet
^ For piston cooling
8 - Bearing shell
^ Note installed position
^ Do not interchange used bearing shells
^ Ensure retaining lugs fit tightly in recesses
^ Upper bearing shell with oil drilling for piston pin lubrication
^ Axial clearance
- New: 0.05 to 0.31 mm
- Wear limit: 0.37 mm
^ Check radial clearance with Plastigage:
- New: 0.01 to 0.06 mm
- Wear limit: 0.12 mm
^ Do not rotate crankshaft when checking radial clearance
9 - Cylinder block
10 - Connecting rod bolt
11 - Circlip
12 - Piston pin
^ If difficult to remove, heat piston to 60°C
^ Remove and install with VW 222 A
Checking piston ring gap
Special tools, testers and auxiliary items required
^ Feeler gauges
Work sequence
- Push ring squarely from above down to approx. 15 mm from bottom end of cylinder.
Checking piston ring gap
Special tools, testers and auxiliary items required
^ Feeler gauges
Work sequence
- Clean groove before check.
Checking piston
Special tools, testers and auxiliary items required
^ External micrometer 75 to 100 mm
Work sequence
- Measure pistons approx. 10 mm from the lower edge of skirt, at 90° to the piston pin axis.
- Difference between actual and nominal diameter: not more than 0.04 mm
Checking cylinder bores
Special tools, testers and auxiliary items required
Internal dial gauge 50100 mm
- Take measurements at 3 positions in both lateral - A - and longitudinal - B - planes, as illustrated.
- Difference between actual and nominal diameter: not more than 0.08 mm
Note:
^ Measuring the cylinder bores must not be done when the cylinder block is mounted on a repair stand with holding fixture VW540 and spacers VW 540/1 B, as incorrect measurements would then be possible.
Piston with industrially cracked connecting rod
Note:
^ When working on the engine, it should be secured with the Holding fixture VW540 and the Spacers VW 540/1 B to the support clamp.
1 - Piston rings
^ Gaps offset by 120°
^ Remove and install using piston ring pliers
^ "TOP" faces piston crown
2 - Piston
^ Mark with installation position and cylinder number
^ Arrow on piston crown points to belt pulley end
^ Install using piston ring clamp
3 - Piston pin
^ If difficult to remove, heat piston to 60°C
^ Remove and install with VW 222 A.
4 - Circlip
5 - Connecting rod
^ With industrially cracked bearing caps
^ Replace as set only
^ Mark with cylinder number - B -
^ Installation position: Marking - A - faces belt pulley end
6 - Bearing shell
^ Note installed position.
^ Insert bearing shells centrally
^ Do not interchange used bearing shells
^ Check for secure seating
^ Axial clearance
- New: 0.10 to 0.35 mm
- Wear limit: 0.4 mm
^ Check radial clearance with Plastigage:
- New: 0.01 to 0.05 mm
- Wear limit: 0.09 mm
^ Do not rotate crankshaft when checking radial clearance
7 - Cylinder block
8 - Connecting rod bearing cap
^ Note installed position
^ Caps only fit in one position and only on appropriate connecting rod due to breaking procedure (cracking) separating cap from connecting rod
9 - Oil spray jet
^ For piston cooling
10 - Pressure relieve valve, 27 Nm
11 - 30 Nm plus 1/4 turn (90°)
^ Replace
^ Oil threads and contact surfaces
^ To measure radial clearance, tighten to 30 Nm, but do not turn further
Checking piston ring gap
Special tools, testers and auxiliary items required
^ Feeler gauges
Work sequence
- Push ring squarely from above down to approx. 15 mm from bottom end of cylinder.
Checking piston ring gap
Special tools, testers and auxiliary items required
^ Feeler gauges
Work sequence
- Clean groove before check.
Checking piston
Special tools, testers and auxiliary items required
^ External micrometer 75 to 100 mm
Work sequence
- Measure pistons approx. 10 mm from lower edge of skirt, at 90° to piston pin axis.
- Difference between actual and nominal diameter: not more than 0.04 mm
Installation position of bearing shells
Bearing shell - 1 - with oil drilling - arrow - for connecting rod.
Bearing shell - 2 - with no oil drilling for connecting rod bearing cap.
- Insert bearing shells centralized in connecting rod and connecting rod bearing cap.
- Dimension - a - must be same on left and right sides.
Checking cylinder bores
Special tools, testers and auxiliary items required
^ Internal dial gauge 50 to 100 mm
- Take measurements at 3 positions in both lateral - A - and longitudinal - B - planes, as illustrated.
- Difference between actual and nominal diameter: not more than 0.08 mm
Note:
^ Measuring the cylinder bores must not be done when the cylinder block is mounted on a repair stand with holding fixture VW540 and spacers VW 540/1 B, as incorrect measurements would then be possible.