Lower unit oil

[g352nv]

I have a ratchet with a flat head socket. Works great.

[bill.s]

Big screwdriver real tight in the slot with a small adjustable wrench on the flat of the screwdriver has always worked well for me.

[RazorCat]

In place of a handheld impact driver, a big flat screw driver and a few gentle persuasive taps have been known to do the trick.

This^^^
Biggest flathead that will fit the plugs, tap lightly on the screwdriver handle with a hammer, use Channelock pliers to turn the screwdriver while pressing firmly against the end of the screwdriver. Once you feel the plug “pop”, you’ve got it. I have a large flathead dedicated to only removing lower unit plugs. As g352nv states, a ratchet with a flathead attachment will work well too.

[dartag1829]

Get an Impact Driver like mentioned above. Have to use one on my Mercury once and a while.

[g352nv]

What oil you guys running?

[RazorCat]

What oil you guys running?

Mercury or Quicksilver High Performance

[marinetechnician]

Mercury or Quicksilver High Performance

Yup , best gear oil out there IMO. Don't reuse the gaskets either.