Hi i have a 1997 xk8 i am changing the timing chains and i am stuck knowing how to identify when i replace the 2 smaller chains if i have the orientation correct where the JTIS reads 1/2 a tooth out of align.


i dont understand what this picture correlates to, where is the reference gear cog in reality?




the original reason for this timing chain replacement, a failed primary timing chain tensioner.




both sprockets each side




i am not sure if this is the offset, the gear moves round the other gear so its hard to judge?

I think I'm correct in saying that the sprockets in the JTIS diagram are the two CRANKSHAFT sprockets. Engine timing is determined by the position of the crankshaft (special tool in the "timing disc / torque convertor") and both camshafts with horizontal "flats". So - if crankshaft and four camshafts are in the correct position, there's no specific correct alignment for the four camshaft sprockets.

thanks, i have them both locked down

The reference is to the sprockets on the crankshaft, not the camshaft- if you look you will see they are 1/2 tooth off front and back.

+1. You should be good to go. If you have the cams locked, it will be easy to align those crankshaft sprockets.