Gentlemen,

For a little while now I have been working on building a long tail for a small layout boat (5hp) and am finally reaching the final stages but can't figure out how to water tight seal it. I don't want to rip my surface drive apart too much to look so before I do that can some one post pics of how theirs is sealed? I used a 3/4 shaft which maybe too much steel for that little motor, should I go smaller? Last step in a long process that will get me to the ducks!

Thanks!

Here's a great way to get the exact seal you need.

Go to


and scroll to the section (p46) where they list all the sizes made. Copy the part number and do a search at any online auto parts place. I like because they will ship a single seal in a 1st class mail pkg for like $1.22 so you don't get hammered on shipping.

For instance a 3/4 ID x 1.575" seal (for a standard 40mm OD x .750" ID bearing) is Timken P/N 471498. Go to Rock Auto under parts search and put that in and you come up with a hit. You may have to search a few different part numbers with the same size to get a match.

I have all the parts for my long tail. Just have to do some machining and put it together. I am using a 1.375" OD steel tube with a 1.25" ID for the main housing. My shaft is 3/4" so the seals (two at the prop end) I need are Timken 470954 and Rock Auto has them for $1.66 each. My upper housing will have a hub with a 40mm OD bearing and it uses the 3/4 x 1.575" seal.

Sandor27

If you dont have a 10tpi 3/4" shaft you will never find a prop.

mcmaster carr has just about every seal you could need. I used 4 in the tail end, 2 put in backwards and 2 put in the right way, first 2 keep the water out and the inner 2 keep the grease in. Top end has 2 seals in the right direction to keep grease in. I put RTV around the outside edge of the seal before I drove it into the tube to help it seal against the inside of my tube

On the ones I've built, I do not build up a bearing/seal housing on the lower end. My main tube has a 1" ID and I use seals with a 3/4" ID x 1.01" OD. I sandwich two of them in between a straight bronze bushing and a bronze flange bushing. The flange bushing is merely to protect the seals from damage should the prop ever get wrapped up in fishing line or anything else that would slice through them.

Where did you find them barrings and seals

I set my long tail up like the pictuire above. I used bushing # 6391k269 for the plain bushing and the seals were #5154T56. I used 3 plain busings, and 5 seals. Both came from McMaster - Carr. I found the picture above after I started, and had to buy the shouldered bushing at the local farm store. No real time on it yet, but it seems to keep the grease in.

Hope this helps.

Mudde