S54.30-0007-01
1.1 Unscrew speedometer sensor (G4) on manual transmission, disconnect cables and insulate.
Except models 638.094/194/294.
1.2 Unscrew cover on transmission.
In models 638.094/194/294 the cover is located on the front left next to the opening of the clutch operator vent valve.
S54.30-0523-01
2 Screw tachograph sensor (G3) onto manual transmission.