If its not the timing chaing rattle (light ticking/clacking) then its probably the starter bendix binding within the starter.
The fix is to replace the starter, at least the most efficient fix is so.
Damage to the flywheel can result, leading to flywheel replacement, if this is your problem.
All of this assumes that the car DOESN'T start when you try.. it grinds. Upon retrying it may start. If the car actually STARTS every time, just grinds (and it isn't the clacking timing components) then the shimming method CAN help, though I havcen't the foggiest how to explain it, nor where the post about that is.
Ray