Reply To: Lower unit lubricant

[David Stanton]

I use marine gearcase oil in my 3 HPs that are like yours.  Be sure to use Marine gear oil.  Regular gear oil for cars does not have the additive to emulsify any water that gets in, which helps prevent rust and keeps it all in suspension, and lubricating until really a lot of water gets in.  You may need the seal on the prop shaft – not the big O-ring you replaced.  There is also a seal where the driveshaft goes in, under the water pump impeller.  It’s these two seals that usually leak – not the O-ring.

Dave