How to change oil in your Magnacharger MP112
 

Note, the Magnacharger recommended oil change interval is 100k miles.

Tools needed:
4.5 allen (hex) wrench
empty water bottle
small measuring cup
small flexible plastic hose about 2 feet long, maybe 1/3" or less outside diameter, or a brand new empty plastic spray bottle (don't reuse an old one that had some cleaning product in it)
Two 4oz GM Supercharger oil bottles, part #12345982 (about $12 each)
paper towels

Time: 20-30 minutes

Skill level: Easy cheesy

Opening up the drain plug

After the truck is warm so that the oil is warm and flows more easily, remove the allen wrench drain plug on the front snout of blower. Oil will not come gushing out, but I would put a paper towel below to catch drips. Don't drop the bolt, that could ruin your day.

Removing the old oil

Stick the plastic tube down in the hole and siphon the oil out into the water bottle. I used my mouth, it worked fine with none going in my mouth. (A video on youtube shows a guy using the spray part of a Windex-type nozzle with the tube stuck in the supercharger to spray the oil out, but you should buy an empty one as ones that had degreaser or Windex in them can contaminate the oil with ammonia or other stuff. Costs $1-2 at WalMart, so not worth the risk.) About 4oz should come out, so you don't need an enormous water bottle. My oil came out looking like chocolate milk (the new oil is clear), so I'm glad I changed it.

Refilling

Measure the oil removed with your measuring cup so you know how much to put back in. I removed exactly 4oz from the blower and couldn't get anything else out, but I would check for yourself to avoid over/under filling it. The bottle of oil should have a squirt top. I used another section of my plastic hose and slipped it on top of the squirt top so I could see the oil going in and hold the bottle vertically. Refill the supercharger with the same amount of oil you removed. Dry fill is 5oz, but the Magnuson rep said make sure not to overfill it, so only replace what you pull out.​​​​​​​

Wrap up

Once I had all of the oil in there, I cleaned off the plug, and reinstalled it. I snugged it down with the wrench, but didn't crank it down as you risk stripping the bolt.

Dispose of the oil properly. I just dumped it in my oil change tub to be taken to recycling next time I change my oil. That's it. Post up any questions or helpful tips if you have them.

I'll throw some pictures on here later. I didn't take any when I changed it, this thread was an afterthought as I couldn't find a step by step before I changed it.