Piston, Engine

Piston, Connecting Rod Assembly





CAUTION: Do NOT turn crankshaft when measuring radial play.

1 - Piston rings
- offset gaps 120°
- remove/install using piston ring pliers
- "TOP" marking faces top of piston
- checking gap, Testing and Inspection
- checking side clearance, Testing and Inspection
2 - Piston
- checking, Testing and Inspection
- mark installation position and cylinder number
- highest side of piston crown is toward center of cylinder block
- install with tool 3278
3 - Connecting rod
- replace in sets only
- markings B (inset) indicate cylinder number
- markings A (inset) must be on top of each other
4 - Connecting rod cap
note installation position
5 - Connecting rod bolt
- Use old bolts to check radial play, tighten to 30 Nm (22 ft lb), do NOT tighten further
- always replace
- new bolts tighten to 30 Nm (22 ft lb) + 114 (90°) turn
6 - Bearing shell
- note installation position
- do NOT interchange used bearing shells
- retaining tabs must fit securely
- end play,
New 0.05-0.31 mm (0.002-0.012 in.)
Wear limit. 0.4 mm (0.016 in.)
- radial clearance, with Plastigage,
New. 0.01-0.06 mm (0.004-0.002 in.)
Wear limit. 0.10 mm (0.004 in.)
7 - Cylinder block
- checking cylinder bore, Testing and Inspection
- piston and cylinder dimensions, Specifications
8 - Piston pin
- remove and install with tool VW 222a
- it difficult to remove, heat piston to 60° C (140° F)
9 - Circlip