Hi found the fault with my no starting corsa..well hope i have took off rocker coever and could almost lift the timing chain off the sprockets, and couldnt get both cams to point outwards at TDC so presume it has jumped a few teeth, hence compression of 180 on all cylinders. So I have brought a new chain kit and sprockets and the tools, BUT reading the good old haynes book it mentions a new bolt for the cankshaft pully wheel and taking off the sump so i presume a new gasket is needed here? non of which are supplied in any of the kits.....do i need to change these? planning on doing the job over the weekend so need to get bits tomorrow..please help if you can...thanks