I have a 2000 Volkswagen Jetta 1.8 Turbo GLS. I had to replace the camshaft chain tensioner. I set the timing belt sprocket to TDC and looked at the chain gear on the other end of the camshaft there is suppose to be a notch on the gear that lines up with an arrow on the top of the bearing cap and it is not. The notch in further down on the gear. Both gear and sprocket are suppose to be keyed I think. What could have caused the notches at top dead center to be off on the chain gear.