Ok thanks for everyones help ill post how i go tommoro fingers crossed.. and as for chamfer what does this mean?

Well for those that ever make the same mistake we used a m14 1.5 tap and gently ran the tap through it worked well.. then to get the new balancer on we used a longer bolt to pull it in a bit then tapped it with a hammer then did the bolt up more and tapped again so on so on.. all good now, cheers for everyones help

yep, longer bolt to grip more thread, glad you had it work out....... because it can be a big headache otherwise