I have a 97 impreza outback which makes a loud noise when in tight turns. You can hear it and feel it in the rear of the vehicle. I heard and read this could be clutches in the transfer case. I installed the fuse in the FWD socket and the problem went away. As i understand installing the fuse eliminates the rear wheel drive and make it front wheel drive only. I would like to fix the problem but I have heard that adding a differential additive to the transmission may help with this problem. The only question I have is will using this additive have any negative impact on the rest of the transmission?