Assembly Overview
Assembly overview
Conventional connecting rod
1. Piston rings
- Offset gaps by 120°
- Use piston ring pliers to remove and install
- "TOP" faces towards piston crown
- Checking ring gap, Refer Fig. 1
2. Piston
- Checking, Refer to Fig. 3
- Mark installation position and cylinder number
- Arrow on piston crown points to belt pulley end
- 2-part oil scraper ring
- Checking piston ring-to-groove clearance
- , Refer to Fig. 2
- Install using piston ring clamp
3. Connecting rod
- Only replace as a set
- Mark relation to cylinder-B
- Installation position: Marking -A- faces belt pulley end
4. Connecting rod bearing cap
- Mark relation to cylinder-B
- Installation position: Marking -A- faces belt pulley end
5. 30 Nm plus an additional 1/4 turn (90°)
- Always replace
- Oil thread and contact surfaces
- To measure radial clearance tighten to 30 Nm, but do not turn further
6. Bearing shell
- Observe installation 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: 0.10 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
7. Cylinder block
8. Connecting rod bolt
9. Circlip
10. Piston pin
- If difficult to remove, heat piston to 60°C
- Remove and install with VW 222A
Industrially cracked connecting rod
1. Piston rings
- Offset gaps by 120-
- Use piston ring pliers to remove and install
- Manufacturer's mark faces piston crown
- Checking ring gap, Refer to Fig. 1
- Checking ring to groove clearance, Refer to Fig. 2
2. Piston
- Checking, Refer to Fig. 3
- Mark 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 222A
4. Circlip
5. Connecting rod
- With split bearing cap
- Only replace as a set
- Mark relation to cylinder-B
- Installation position: Marking -A- faces belt pulley end
6. Bearing shell
- Observe installation position, Refer to Fig 4
- Insert bearing shells centrally
- Do not interchange used bearing shells
- Check seated securely
- Axial clearance, New: 0.10 ... 0.35 mm; Wear limit: 0.4 mm
- Check radial clearance with Plastigage: New: 0.01...0.05 mm; Wear limit: 0.09 mm (Do not rotate crankshaft when checking radial clearance)
7. Cylinder block
- Checking cylinder bores, Refer to Fig 5
8. Connecting rod bearing cap
- Observe installed position
- Caps only fit in one position and only on appropriate connecting rod due to breaking procedure (industrially cracking) separating cap from connecting rod
9. 30 Nm plus an additional 1/4 turn (90°)
- Torx E10
- Replace
- Oil thread and contact surface
- To measure radial clearance tighten to 30 Nm, but do not turn further
Fig. 1 Checking piston ring gap
Special tools and equipment
- Feeler gauge
Work sequence
- Push ring squarely from above down to approximately 15 mm from bottom end of cylinder.
Fig. 2 Checking ring to groove clearance
Special tools and equipment
- Feeler gauge
Work sequence
- Clean groove before checking.
Fig. 3 Checking piston
Special tools and equipment
- External micrometer 75 . .. 100 mm
Test sequence
- Measure pistons approximately 10 mm from lower edge of skirt, 90- offset to axis of piston pin.
Deviation from nominal dimension: max. 0.04 mm
Fig. 4 Installation position of bearing shells
Bearing shell -1- with oil channel (arrow) for connecting rod.
Bearing shell -2- without oil channel connecting rod bearing cap.
- Insert bearing shells and connecting rod bearing cap centrally.
Dimension -a- must be same on both left and right side deviation: 0.2 mm.
Fig. 5 Checking cylinder bores
Special tools and equipment
- Internal dial gauge 50 . 100 mm
- Measure bores at 3 locations in both directions -A- across engine and -B- in line with crankshaft.
Deviation from nominal dimension: max. 0.08 mm
Note: Measuring of the cylinder bores must not be done when the cylinder block is mounted on a repair stand with adapter bracket VW 540, as incorrect measurements would then be possible.