I am only familiar with turbos, but when I bough the previa, I had to look at supercharger info.

http://auto.howstuffworks.com/supercharger.htm


I just recently changed out my supercharger oil and according to the maint records I got when I bought the van, there wasn't any information on the supercharger every being touched.

Every since I got my previa, I planned to do it, but procrastinated and forgot about it. But last weekend I was taking apart my van and decided to finally do it. The oil smelt burnt.

I can't comment on the belt as mine is not slipping, but I can explain what I did for the oil change.

when you go underneath your van, and look at the supercharger, there is a drain bolt on the bottom, It is a 17mm. I think the most annoying part is getting a tiny hose, snaking it up to the dip stick opening and injecting (with syringe) fluid. It wasn't hard, but my initial hose wasn't small enough. I also did this in my underground parking garage, which is dimly lit.

https://youtu.be/i0wjomTduSw