The main timing chain tensioner, how do you activate it/preload what ever you want to call it lol. Someone on vectra c forum said to just put it into some clean engine oil and keep pressing it till its hard to do then its activated. I thought you had to get circlip out which i cant do with circlip pliers and twist the bit inside clockwise or anti clockwise i dont remember and put back together then press it with a blunt lever from down behind chain and rail when finished. And for the life of me i csnt get the chain to line up to the 3 marks when i put balance chain on. Got inlet sprocket at 12 oclock, exhaust at 6 oclock and crank at 6 oclock.