I've been restoring our Grandprix GTP, to give my son something of a first car, and I had to start with rebuilding the M90 supercharger. I thought I would post it here, in case someone was curious about what was in side one, it's a first for me too. I changed out four bearings,shaft seal, and a rubber coupler, grand total $70. Replacement GM would be about $1200 . Just got the car back together, and besides a bad plug wire that I had to replace, the thing runs beautiful . If my wife caught me doing that on her washer/dryer, she would of killed me for sure, but I left no evidence, so it's cool.