otherwise this happens to your crank keyway and crankshaft sprocket...





that's almost one tooth of play in either direction as a result of that damage. I rebuilt the engine 20,000kms ago and it seems I didn't tighten the crankshaft pulley bolt up to the correct torque (which is 195Nm if you were wondering)

I only discovered it after I had to remove the cambelt



to remove the upper 'cam tray' from the front cylinder bank



in order to replace a tappet, which due to the inferior design does this



when it's meant to look like this



which you can only replace it by accessing the underside of the cam tray





so yeah.. I fixed one problem only to discover a major problem. looks like the crank is going to come out to be repaired :(