Chances are the oil is still in there. It's supposed to last the life of the supercharger. You'll see on the back end (opposite the pulley end) There are a couple of bungs. One in the bottom, and one in the side. The bottom one is a drain, the side one has a dipstick on the bottom of it. The S/C12 off the 4AG-ZE has a yellow wingnut on the dip/fill bung, whereas the S/C14 just has a bolt hex on it. The oil is usually bought from toyota. It costs more than 30 year old scotch. They only take about 130 odd mls. Just unscrew your fill bung (With the blower vertical, IE over and under, rather than side by side) and see how much oil is on the dipstick. If you find that your blower is using oil, it's time to find a new blower. I've never heard of anyone rebuildoing one of there units. I'm not saying it can't be done, just that I don't know anyone who has.......