SD31 saildrive oil level?

[andreas.mehlin]

Opened the cap to check oil level and it was filled all up and flowed over. Boat is on the hard and dont know how prev owner filled. So My question is, how full shall it be?

2nd question. There is an electric wire going to the saildrive. What is it for?

[piloto]

I’m only guessing but usually there’s a square plug on the side of housings that, when removed, allows flow out when fluid has reached the proper level. This is somewhat universal for transmission cases, etc. The wire (maybe green?) might be a bonding ground that runs to a common ground buss bar or daisy chains to another metal fixture. This would be to prevent electrolysis and accelerated degradation.

[Lizzyfish]

The wire is a water sensor. It will trigger an alarm if there is water between the lower hull to saildrive seal and the upper saildrive to hull seal. Most saildrive have no lower drain, you remove prop shaft end cap. Just fill from the top of the sail drive, should be 1 inch from the top plug.

[Lizzyfish]

The wire is a water sensor. It will trigger an alarm if there is water between the lower hull to saildrive seal and the upper saildrive to hull seal. Most saildrive have no lower drain, you remove prop shaft end cap. Just fill from the top of the sail drive, should be 1 inch from the top plug.

[Privilege]

I'm with Lizzy - The wire is for the water sensor which tells you if the outer diaphragm has failed and water is getting in.

The cap of the SD usually has a dipstick built in. The fluid shouldn't be completely full as it will expand when it gets warm. The dipstick is about the length of your forefinger...unless you have really weird fingers.

[DotDun]

Doesn't the cap have a dip stick on it?

Is the oil milky color? If yes, the lower seal is out and it's sucking water, may be the reason it's overfull....