Backstory: Bought a new fan clutch a few years ago when I was rebuilding the engine. Alas, when I installed it I felt like it wasn’t pushing enough air so I put my old one back in. The old one spins a lot of air and roars most of the time, so it gets the job done but I wanted my new one in the cruiser to go with my new radiator. New fan clutch, splitting and de-oiling: Yesterday, I used a manual impact driver to get the overtightened screws out, then separated the half’s. The oil level only reached part way up when looking at the 4 holes. It wasn’t filled to the top, probably only half full. I wasn’t sure which half stores the oil though, the half with the valve or the half with the gasket groove and 4 holes. Flipped both upside down and oil only came out of the half with the groove and 4 holes. If I had to guess only 1 bottle’s worth came out, around 18 ml. I’ve read that two 18ml bottles is what he factory puts in but mine appears to only have had one. Adding oil: After draining the factory oil, I added around 18ml of 10,000 cst that I picked up from a hobby store and 15 ml of Toyota 3000 cst. This amount filled up the 4 holes completely to the top. I added a total of 33 ml and combined I should have a cst of something between 6000 - 6500 cst. I don’t know if any oil is stored behind the closed valve in the other half. I had read about people heating it up in an oven and draining it, so I don’t know if it’s over full now (since I didn’t do that) but I’m going to run with it and see what happens.