I have read different things in different threads but it's hard to get a clear picture on this subject. Some people have no noise, some have a "normal" noise. So what do you experience from your AYC, and how long have you had that noise? People say they love hearing the AYC going nuts and it's something they've never heard before. My experience is a little odd. I should note that I had my diff and AYC fluids changed by a workshop yesterday and the noise is not as loud but it's still there. Normal driving I can't hear anything. If I am going around a corner and one bar lights up I hear what I can only describe as "screeching" like a tyre screeching. It's loud enough to think it is actually one of your tyres skidding. I know it's not a tyre because you can't hear it outside the car, that and it happens when you're not going fast enough to actually be skidding. If I get up to a second bar whilst accelerating away I get a louder screech, but sometimes I get another noise which kind of sounds like something scrubbing or a really horrible grumble. I really don't like it, I doubt that noise is the AYC. But the screeching is still there. The one time I got a third light was going around a roundabout in the dry, had lots of tyre squealing but again, that same noise just got noisier from the diff. If I go onto wet grass or something and give the car a bootful and light up all three bars in a straight line I don't think it made a sound, either that or I was just holding on from the unexpected acceleration! So yeah. All my experience seems to be having bars light up in a straight line makes no noise, it's only when going around corners that it happens. That grumble I mention I am treating as something else, I will be checking bearings and all sorts this weekend to see if anything's got play in it. That grumble is only really obvious when you throw the car into a turn, hence maybe too much lateral movement and maybe a wheel scrubbing. That's what I am after. What do you consider "normal" noises, what noises have you had that you've fixed (eg. I had that squeal, the mechanic used the wrong AYC fluid, put XXX in it and the noise went away!), all that jazz. It's just confusing there's so many threads about AYC that each one turns into a conversation about something entirely different! Surely if AYC was that noisy Evo owners would have complained about it. If my turbo's and BOV are so quiet to keep the 50 year old legnum owner happy, why have a diff that's so obviously loud from factory?