To anyone who is an expert/engineer, Is 3thou run out a good enough tolerance across a flywheel face, or will it cause an In-balance and judder?? Also, is there a slight 'ridge' at the end of the contact area of the friction plate (Standard MY99 10.5kg), or is that where its worn as one person suggested??. Also, any rules to consider when 'skimming' a flywheel?? (eg, lightening etc)

 

The run out sounds ok to me. The step is indeed wear. The surface finish is critical, have it reground by a real engine shop, not just a machine shop. They will know what to do and what surface to provide. They can also check/correct any balance issue. Balance is critical especially if it's an STi at 8000 rpm.....
Graham.

 

So, they will need to go out past the ridge mark which is on the outside diammeter of the Friction plate area? How can they skim the whole surface of the flywheel with the 2 dowel pins?? Can these be removed then?

 

Yes. they drift out easy. They will do that and put them back in.
Having this lot done to my lightweight wheel now as it happens!
Graham.