The cams can move sharply like that, happens because of valve spring tension nothing to worry about. Just keep your fingers out of the cam gear, that thing snaps back like that and it can do some serious damage!

 

no joke man that could rip a finger off- what kind of tolerances does the timing of the cam gear have for true tdc- because i was looking at this thing for hours and you know if you stare at a straight line when you're tired you can make it crooked- especially on the left cam that snapped - from one angle it is straight on but from another its off and you can't really get a straight line sight at the left cam - it looked like it might have been like a quarter or half tooth off but the mark on the front side of the belt was straight on and there was no more play in the belt to move it - that belt was tight so it might have been an optical illusion from the angle i was standing at- and on top of it the installation mark on the belt was not straight, seriously it was crooked i looked with a straight edge- so i went by the mark on the cam itself, but it still could have been a little off

 

The marks between the cam and cover never line up exactly. I found the 1MZ-FE to be really close, the 3VZ-FE bank 2 seemed more out to me. 2VZ-FE same deal. Which is why I love having the marks on the belt, no guess work and staring at the marks for an hour wondering if you did everything right.