Hi guys,thanks for all the input.This is where I am at the moment.I have had it confirmed that my 4/4 sport was converted to competition spec by Revolutions up in Perth who converted it to go racing.It has throttle bodies,LSD,roll bar,AVO,s,panhard rod,etc,etc.After listening to all your comments and talking to Revolutions my next course of action is to replace the medium priced diff oil I purchased(with friction modifier)for some very expensive(£215 for 2.5 litres)diff oil+friction modifier,as advised in gomog.I will give this a go and report back to you with the result.Revolutions have said that if this does not cure the "ringing howl"I can take it back to them for investigation.
