Golf Mk4
Dismantling and assembling pistons and conrods |
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 | Check → Fig.. |
q | Mark installation position and cylinder number. |
q | Arrow on piston crown points to belt pulley end. |
q | Install using piston ring clamp. |
3 - | Piston pin |
q | If difficult to remove, heat piston to 60° C. |
q | Remove and install using drift -VW 222 A-. |
4 - | Circlip |
5 - | Conrod |
q | Renew as set only. |
q | Mark cylinder number -B-. |
q | Installation position: markings -A- face towards belt pulley end. |
6 - | Bearing shell |
q | Note installation position → Fig.. |
q | Do not interchange used bearing shells. |
q | Insert bearing shells centrally. |
q | Axial clearance new: 0.05…0.31 mm , wear limit: 0.37 mm. |
q | Check radial clearance with Plastigage: new = 0.01…0.06 mm; wear limit = 0.09 mm. Do not rotate crankshaft when checking radial clearance. |
7 - | Cylinder block |
q | Checking cylinder bores → Fig.. |
q | Piston and cylinder dimensions → Chapter. |
8 - | Conrod bearing cap |
q | Note installation position. |
q | Due to the cracking method used to separate the bearing cap from the conrod in manufacture, the caps only fit in one position and only on the appropriate conrod. |
9 - | Conrod bolt, 30 Nm + 1/4 turn (90°) further |
q | Torx E 10 |
q | Renew. |
q | Oil threads and contact surface. |
q | To measure radial clearance, tighten to 30 Nm but not further. |