I'll be finishing up my longtail build tomorrow and was just curious if anyone fills their driveshaft tube with oil instead of using grease. If you do this, what kind of fittings do you use to put the oil in and where can you get them? I've been looking around for ways to put oil into the driveshaft housing above and below the center bushing, but haven't really found much. Thanks for the help guys.

use grease. forget the oil.

Any reason for using grease over oil? My deal is that once that shaft gets spinning, especially for extended periods of time, it will sling the grease out of the bushings and has a higher likelihood of overheating. With oil, it will have a constant supply of lubrication AND disperse some of the heat inside the housing. Just my thoughts, but I always like to learn, preferably not the hard way

If its gonna throw out grease, its gonna throw out oil.

I have been thinking about using cornhead grease when I get mine built. Cornhead grease will turn into a liquid around things that get hot. Im thinking that around my bushings the liquified grease will seep into the bushings better.

You guys are overthinking it. Simple and easy is better, grease is all you need. If you go with oil you are going to need some bulletproof seals to keep it in the shaft. Regular grease gets really runny as it heats, and will flow into the bushings fine. I used Oilite bushings with a grease channel on my last build, even after running for an hour or so the shaft around the bushings isn't more than warm.

The grease stabilizes the shaft to.

Grease for sure. My first LT from GD back in 1986, an 18 HP Briggs, was a greasy mess, even with new seals. I carried my grease gun with me as I was counseled then by Warren Coco. He said he'd regularly change out the sleeve bearings two or three times a season! I must say when I switched to an MB LT in 2004, the roller bearing system experiences a lot less grease loss but loses it just the same- but I don't carry my grease gun in the boat any more only the shotguns . I have been using synthetic grease (Mobil 1 or other) and I know it is expensive but it definitely reduces friction more than the graphite stuff. Of course regular bearing grease, Aqua-lube, or other marine bearing grease will work just fine.

I just built one and used gear oil. I put three seals on the lower end and one on the upper. I have about 8 hours on it so far and the bottom seals are still holding good. I had the u joint slip a little and got the shaft out of alignment and it dumped my oil reservoir in a minute. What a mess. I think after the season I will convert to grease with a pressure lubricator like a GD. I am having a restating problem when hot so I am no expert but that's my 2cents.