Hi I am about to take the head off my motor and have studied the C D workshop manual but I cannot relieve the tension on the timing chain I have been told you can take the sprocket off without relieving the tension but there is a chance the plunger can jump out and fall down inside the casing would appreciate any advice about this and anything else I should be aware of. I have not done an overhead cam job before so am a bit worried in case I bugger something up any advise would be much appreciated cheers from a new member