Volkswagen Workshop Service and Repair Manuals

Assembly overview

1 -	Piston rings

q	Offset gaps by 120°.

q	Use piston ring pliers to remove and install.

q	„TOP“ faces towards piston crown

q	Checking ring gap → Fig..

q	Checking ring-to-groove clearance → Fig..

2 -

Piston

q	Checking → Fig.

q	Mark cylinder number and installation position relative to conrod.

q	Low point of piston crown faces to centre of cylinder block.

q	Installing piston → Fig..

3 -

Circlip

4 -

Conrod

q	Renew as set only.

q	Mark cylinder number -B-.

q	Installation position: marks -A- must be above one another.

5 -	Bearing shell

q	Note installation position.

q	Do not interchange used bearing shells.

q	The lugs on bearing shells must fit tightly in the recesses.

q	Axial clearance:

q	New: 0.05…0.31 mm.

q	Wear limit: 0.40 mm

q	Check radial clearance with Plastigage:

q	New: 0.02…0.07 mm.

q	Wear limit: 0.10 mm

q	Do not rotate crankshaft when checking radial clearance.

6 -	Conrod bearing cap

q	Mark cylinder number -B-.

q	Installation position: marks -A- must be above one another.

7 -	30 Nm + 1/4 turn (90°) further

q

Renew.

q	Oil threads and contact surface.

q	To measure radial clearance, tighten to 30 Nm but not further.

8 -	Cylinder block

q	Checking cylinder bores → Fig..

q	Removing and installing crankshaft → Chapter.

q	Piston and cylinder dimensions → Chapter.

9 -	Piston pin

q	If difficult to remove, heat piston to 60 °C.

q	Remove and install using drift -VW 222 A-.

Checking piston ring gap Special tools and workshop equipment required t  Feeler gauges Test procedure –  Push ring at right angles from above down to approx. 15 mm from bottom end of cylinder. Push in using a piston without rings.

Piston ring		Ring gap
		New	Wear limit
Rectangular-section ring	mm	0.20...0.40	1.0
Tapered stepped ring	mm	0.20...0.40	1.0
Oil scraper ring	mm	0.25...0.50	1.0

Checking ring-to-groove clearance Special tools and workshop equipment required t  Feeler gauges –  Clean annular groove before check.

Piston ring		Clearance
		New	Wear limit
Rectangular-section ring	mm	0.04...0.09	0.15
Tapered stepped ring	mm	0.03...0.06	0.15
Oil scraper ring	mm	0.02...0.06	0.15

Checking piston Special tools and workshop equipment required t  External micrometer 75…100 mm Measure approx. 6 mm from lower edge of skirt, at 90° to piston pin axis. Deviation from nominal dimension max. 0.04 mm

Checking cylinder bores Special tools and workshop equipment required t  Cylinder gauge 50…100 mmf Test procedure Take measurements at 3 positions in both lateral direction -A- and longitudinal direction -B-. Difference between actual and nominal diameter max. 0.08 mm.   Note Cylinder bores must not be measured when the cylinder block is mounted on engine and gearbox support -VAS 6095- or engine and gearbox support -VW 540-, as measurements may be incorrect.

Installing piston Special tools and workshop equipment required t  Funnel -T10147- t  Funnel -3278-   Note t  For engine codes BFH, BJS and BML install using funnel -T10147- t  For engine codes AQP, AUE and BDE install using funnel -3278- t  If a new piston fitting tool is used to install the pistons, first pass piston with oiled piston rings twice through the tool and then remove any resulting metal shavings. Only then install piston with piston rings. Procedure –  Push piston into oiled piston fitting tool by hand. Low point of piston crown must face lug on funnel-arrow-. –  Hold piston fitting tool (with piston inserted) on upper edge and press piston in with both thumbs. –  Push piston in until it protrudes approx. 15 mm from the lower edge of piston fitting tool. –  Place piston in respective cylinder bore. Lug on funnel-arrow- must face centre of cylinder block. –  Hold funnel tightly against cylinder block and push piston in.