Skoda Workshop Service and Repair Manuals

Disassembling and assembling piston and conrod

1 -

Circlip

2 -	Piston pin

q	if stiff, heat piston to approx. 60°C

q	removing and installing with bracket -T10014-

3 -

Piston

q	check → Fig.

q	mark installation position and matching cylinder

q	arrow on piston crown faces towards the belt pulley side

q	Ø Piston = 76.470 mm

4 -	Piston rings

q	Offset joint 120 °

q	use piston ring pliers for removing and installing

q	remove and install 3-part oil scraper rings by hand

q	marking -TOP- must face towards piston crown

q	inspect gap clearance → Fig.

q	inspect end clearance → Fig.

5 -

Conrod

q	always replace as a set only

q	mark matching cylinder -A-

q	Fitting position: Markings -B- point towards the belt pulley side

q	located axially by pistons

6 -	Conrod cap

q	as a result of the conrod separated in the cracking process, the cover fits only in one position and only to the relevant conrod

7 -	Conrod bolt

q

replace

q	M8 - 30 Nm + torque a further 1/4 turn (90 °)

q	M7 - 20 Nm + torque a further 1/4 turn (90°) + torque a further 1/12 (30°)

q	oil thread and head contact surface

8 -	Cylinder block

q	inspect cylinder bore → Fig.

q	Ø Cylinder = 76.51 mm

9 -	Bearing shell

q	do not mix up used bearing shells

q	insert in middle

q	Axial play when new: 0.10...0.35 mm, wear limit: 0.40 mm

Inspecting piston ring gap clearance –  Push in ring at right angles to the cylinder wall from the top through to the bottom cylinder opening, about 15 mm from the cylinder edge.

Piston ring dimensions in mm	new	Wear limit
1st piston ring	0,20...0,50	1,0
2nd piston ring	0,40...0,70	1,0
Oil scraper ring	0,40...1,40	-1)

1) no specification possible for wear limit

Inspect piston ring end clearance –  Clean annular groove before measurement is taken.

Piston ring dimensions in mm	new	Wear limit
1st compression ring	0,04...0,08	0,15
2nd compression ring	0,04...0,08	0,15
Oil scraper ring	cannot be measured

Inspecting pistons Special tools, test equipment as well as aids required t  External micrometer 75...100 mm –  Measure about 10 mm from the lower edge, offset at right angles to the piston pin shaft. Variation compared to basic dimension max. 0.04 mm.

Inspecting cylinder bore Special tools, test equipment as well as aids required t  Internal precision measuring instrument 50...100 mm –  Measure at three points crosswise in a transverse direction -A- and lengthwise -B-. Variations compared to basic dimension max. 0.08 mm.   Note Do not measure the cylinder bore if the cylinder block is fixed to the assembly stand with the engine mount -MP 1-202-, as this may result in incorrect measurements.