the only reason i got the phantom grip instead of the new school lsd is that i heard the new school one was made of 2 differnt types of metal the outside being hard and the inside being a softer metal. So if somehow the outside is worn out the inside would go quickly. Also the phantom has a lifetime gurantee. As far as metal against metal isnt that how the transmission works neways. I dont really see a problem in this way but if u think there is will u please explain it to me becuase i just put in the phantom grip.

Also i broke the pin that held in the diff pin when installing the phatntom grip so i replaced it but i notice a differance in the orginal and the new pin. The orignal cheap and poor quality while the other was solid and had a part at the top that would help it lock in when u put it in.

Also i got the race tunning package with the phantom grip and they offer a differential saver kit which is a new pin u put in the diff and locks on each end somehow and keeps it from coming out
and dont forget about the safing brakets

sorry for the long post