1997 M40C Lower Unit

[MarvinGabriel]

Hello all, from Lake of the Ozarks region. I've come across an M40C that runs well in a tank, but I had no idea of the maintenance lever of the previous owners, so I drained the lower unit. When I pulled the drain plug and level check plug, what came out made me a bit nervous. It was about 2 ounces of black thick, somewhat (foamy) oil, and I think a few drops of water. I filled it from the top to flush out anything else that may be in there, until it ran clear. Replaced the plugs and turned the prop...it doesn't feel smooth, like I'd expect. It feels kind of mechanical and maybe a tiny bit rough. Not really rough, but not bearing smooth. I'm used to auto maintenance, engine rebuilds, etc...but I've seldom delved into boat motors, so I really don't know what to expect. Any advice?

 

[pvanv]

If there was water, you need a seal kit. While apart to replace seals, inspect gears. They typically turn smoothly.

 

[MarvinGabriel]

Thanks, Paul. I'll order a seal kit and water pump kit today. It's a bit smoother today, after sitting in the fresh oil, but i'll try to check everything out when I do the seals.

 

[MarvinGabriel]

Where do I order the parts for this? I've looked, and can't seem to find it, unless I want to wait 20 days.

 

[pvanv]

Any dealer. You can PM me if needed.

 

[Sea Rider]

While the parts are to be delivered, fill with new gear oil the lower leg from the bottom till oil comes out the upper plug. Go for a wot spin for new oil to clean the whole lower case. Remove the new oil till the last oil droplet exits. Proceed to install new parts along adding new gear oil of your brand preference.

Happy Boating

 

[MarvinGabriel]

Thank you. That would be tough to do, since the prop output seal was completely destroyed, and I removed it. I figured I'd have to change the gear oil a few times, because the existing oil was such a mess. I'm cleaning all of the parts in my parts washer, then letting them sit in fresh gear oil, while I wait for parts.