Okay this is basically the deal. Bought an S3 amk and has a load os issues, one I'm dealing with now is the haldex system, When full locking my wheels feel as if they are dragging and locking up. Ive done a haldex oil and filter change and that did nothing. Audi said the only other thing you could do is replace the haldex clutches and controller pump. I sourced these two and took it to a audi specialist to be fitted today. The garage then phoned me and said that with haldex clutches they are designed to only work properly in the diff that they came out of the factory with due to something called a "pinion" and if they did put these clutches into my existing diff it would just whine. Now i spoke to Awesome GTi (Where i bought the haldex controller and clutches from) and they said that they have one haldex clutch replacements before and there has never been a need for finding another diff. They said they just drop in and drop out and all just work. They also said that Audi sell haldex clutches separately so if this was the case they in theory wouldn't work without another diff. Long story short, does anyone know who is correct in all of this? Will the haldex clutches be fine to replace with my existing diff? or will they whine and does this mean i'll need to also buy the diff?? By the way sorry for the life story ^^ lool.