Both of my S4 rotors measured in at about 1 or 2mm UNDER the specified width for rotors. This measurement was in my Haynes/Chilton w/e manual. Why so far under spec? housings came in just fine. Someone wants to purchase one of the rotors, but I don't want to sell them a bad rotor. Whatcha think?

 

are you talking about the seal groove or???

 

sorry, the rotor itself, from side to side. Seal groove is like 2.1mm or something like that. I think that in itself is ok, but the rotor is coming up short width wise.