Piston and connecting rod - remove and install — VW

VW
Gol
1999
Gol
2006
Power unit
4 - Cyl. injection engine (1.0 l)
Edition
06.2014
Piston and connecting rod - remove and install
Note
It is necessary to lubricate support and sliding surfaces before carrying out assembly work.
WARNING
Always replace self-locking nuts and screws subject to angular torque
Piston
Check
Fig.
Mark assembly position and the corresponding position on the respective cylinder.
The piston crown arrow should indicate the direction of the pulley.
Install with the segment ring compressor.
Piston pin
In case of difficulties during removal, heat piston to 60°C.
Remove and install with
Pin
VW 010-206
.
Piston pin retaining ring
Replace.
Connecting rod
Replace complete set only.
Mark corresponding position relative to cylinder
A
.
Assembly position: Markings
B
should point towards the engine flywheel.
On connecting rods without marks
B
, the installation position is the painted faces (connecting rod and cap), facing the crankcase venting device side.
Besides defining the pair (connecting rod and cap), colours painted on connecting rods and caps also define the position (connecting rod in cap).
Piston/connecting rod end clearance 0.20 to 0.40 mm - Wear limit 0.50 mm.
It is separated from cap by the breakage process
Fig.
Bearing shell
Note the assembly position
Fig.
Do not alter position of bearing shells to be reused.
Centre bearing sleeves.
Measure radial clearance with New Plastigage: 0.010..0.00.057 mm. Wear limit: 0.091 mm. Do not turn the crankshaft when measuring the radial clearance.
Engine block
Check cylinder diameters
Fig.
Piston and cylinder dimensions
Chapter
.
Connecting rod caps
Note assembly position.
The connecting rod caps can be fitted in one position only, and exclusively with their corresponding connecting rod.
Besides defining the pair (cap and connecting rod), colours painted on caps and connecting rods also define the position (cap in connecting rod).
It is separated from body by the breakage process
Fig.
Connecting rod screw, 20 Nm + 90°
Replace after each removal.
Lubricate the thread and supporting surface.
To measure the radial clearance, tighten to 20 Nm, without angular torque.
Oil scraper rings
Carefully remove and install the 3-part oil control rings by hand.
The mark
“TOP”
must point towards the piston crown.
Check the openings of the segment ring ends
Fig.
Check ring clearance in piston channel
Fig.
Compression segment rings
Move openings 120°.
Remove and install compression segment rings with ring pliers.
The mark
“TOP”
must point towards the piston crown.
Check clearance of the segment ring ends
Fig.
Check ring clearance in piston channel
Fig.
Typical connecting rods
A
Conventional connecting rods (smooth separation surface).
B
Broken connecting rods (rough separation surface).
Openings of piston ring ends - check
Place segment ring from above so it lies at a right angle on the bottom cylinder opening, at an approx. distance of 15 mm from cylinder edge.
Until February, 2008.
Segment ring
New part
Wear limit
1. Compression segment ring
0.15 to 0.30 mm
1.0 mm
2. Compression segment ring
0.30 to 0.50 mm
1.0 mm
Oil scraper ring
0.20 to 0.60 mm
1.0 mm
From March, 2008.
Ring
Opening gap
new
wear limit
1st compression ring
mm
0,15...0,30
1,0
2nd compression ring
mm
0,20...0,40
1,0
Oil scraper ring
mm
0,25...0,75
1,0
Check ring clearance in the piston groove
Clean segment ring housing channel first.
Until February, 2008.
Ring
Groove clearance
new
wear limit
1st compression ring
mm
0,040...0,075
0,15
2nd compression ring
mm
0,020...0,075
0,15
Oil scraper ring
mm
0,010...0,176
0,186
From March, 2008.
Ring
Groove clearance
new
wear limit
1st compression ring
mm
0,030...0,080
0,15
2nd compression ring
mm
0,030...0,070
0,15
Oil scraper ring
mm
0,000...0,090
0,20
Pistons - check
Special tools and workshop equipment required
Micrometer 60...90 mm
Measure to approx. 10 mm from lower edge, perpendicular to piston pin axis. Difference in relation to maximum nominal dimension: 0.04 mm.
Nominal specification
Chapter
.
Connecting rod bearing shells: installation
1
Bearing shell with bore for piston pin lubrication groove
arrow
.
1 and 2
Bearing shell positions on connecting rod and connecting rod cap
a
right and left sides equal.
a
Maximum tolerance = 0.2 mm.
Note
Both for connecting rod and connecting rod cap, bearing shells provide bores to prevent erroneous installation.
Check cylinder diameters
Special tools and workshop equipment required
a
Precision internal micrometer 50...1000 mm
Measure three different places in cross pattern, both transversally
A
and longitudinally
B
at a distance of 10.0 mm from the upper and lower edges
C
. Tolerances in relation to max. nominal measure 0.08 mm.
Nominal specification
Chapter
.
Note
The internal diameter of the cylinders should not be measured when the engine block is fastened to the assembly stand by means of
Support
VW 540
or
Rotary stand for engine and transmission
VAS 6095
, as this could result in erroneous measurements.