Prop/Rudder Shaft Packing

Anybody do the shaft seals on their Prop/Rudder shafts? How often does this have to be done? I've been avoiding it for some time and I'd like to know how to do it myself to save $$$. The local shops want $500 and say it has to be done every year.

How bad is it leaking? That will tell you if it needs to be repacked or not. If it's a DD do it your self. If it's a Vdrive have someone else go it and by a dripless one so you'll never have to worry about it again.

Do a search and you find a tone of stuff on this very thing

I would seriously consider another shop if they are tellling you that they want $500 for something that has to be done once a year!

Like face planter said, how bad is it leaking? What boat do you have? Do you know the style of shaft seal (packing versus dripless seal)?

A "packing" style will always leak a little bit, at least while running. It is possible to adjust them so that they slow down or stop when the shaft is not turning, but if they rely on a bit of a drip to lubricate the packing. As the packing wears the leak increases. It generally is just a matter of tightening the packing nut a 1/4 turn to slow the leak down to a tolerable level.

The seal types should be able to go a long time without any service. If the seal is wearing out then it is a sign that things are not lined up properly or that the shaft is bent. Seals will usually provide a negligable amount of leakage until they fail. When they fail they can often fail in a big way and create a fairly major leak.

If you have the packing style then the only problem is getting a suitable wrench on the big gland nut. Getting to the prop shaft seal is trivial on a direct drive. On a V-Drive, the "stuffing" box is under the engine, which is often a bitch to get to. The rudder, of course, is located in the very back of the boat and is always a bitch to get to.

If you have the seal variety, then in order to replace the seal you have to pull the shaft/rudder.

If your local shop want's $500 to pull both the rudder and shaft to replace the seal then I would say it sounds a bit high but could be a reasonable amount, depending on how hard it is to get to the rudder. Expecting it to be replaced every year is not reasonable.

Thanks for the replies...Yeah, I was going by the "if it aint broke dont touch it" mantra...The boat is an 86 Supreme, direct drive, so it is the old style packing. I'm not having any problems and leakage is not a problem, it's just that I don't think its ever been replaced. I'm the second owner. The only reason I considered it is because of something one of the guys at the local shop said. I currently am reupholstering the boat so everything is stripped out and I removed the fiberglass floors for cleaning. I figured if there was ever a better time. But if I don't need to do anything, then fine. As far as the rudder goes, I believe it is the sealed type since it has zerk fittings for greasing the shaft, though I could be wrong. I think I may have a handle on the concept, but I wasn't sure how the packing is placed, if it is just wrapped around the shaft and then stuffed into place by the gland nut. Also, there is a rubber hose around the base of the shaft that looks like I would have to pull the shaft to replace. I really don't want to touch it, I'm not sure of its purpose other than to maybe provide water cooling/lube? I'll try posting a pic of the whole thing.

If you decide not to put in a drippless the special rope you buy cost about $10. If a shop does it with all the tools and it should take less than 1 hour. A freind of mine had his v-drive done last year and it only cost him $55 and a v-drive is much harder to do.

On my mastercraft which was the same set up as yours it took me and 2 other guys about 50 minutes to put a drippless on.

They are stroking you.

ask them for a break down in parts and labor.
$55 bucks for the packing gland and $455 for the the rudder shaft seal. I dont think so.

Don't ever go back to that shop, and please post their names here so nobody reading this will go there either.

The rudder looks like a seal type, the shaft is a flax packing.

By chance does the gas tank normally sit over the rudder? If it does, then I would take this opportunity to replace the seal, or at least look into how hard it would be.

Your boat looks very similar to the direct drive ski boat I had a number of years ago. On mine, the steering shaft clamped to the rudder shaft, you have to completely remove (not just loosen) the clamp bolt to get the arm off. Next they will probably be a short coller that is either clamped or held in place by a set screw, which is to keep the rudder from falling out once you remove the steering shaft. Once you remove the collar the rudder should just fall out.

The seal (if there is one) would be at the top of the casting that is bolted to the bottom of the boat. I say "if there is one" because it is also possible that the "seal" is just the amount of grease that is pumped into the shaft housing. There is very little pressure, and the top is pretty close to being above the water line so it doesn't take much to seal.

The prop shaft seal should be easy on this boat. Very easy now, and only a bit harder later. The "stuffing box" is held to the acutual thru-hull fitting by the rubber hose. There will be two nuts on the stuffing box: a thin nut near the hull and then the big cap nut that the prop shaft actually passes through.

To tighten the stuffing box (to slow down a leak) you would loosen the thin nut, then screw the cap nut in a small amount. You do NOT "tighten" it. You just want it to compress the packing a little bit more. Then you hold the cap nut in place and tighten the thin nut up against it to keep it from turning.

Eventually, the packing has been all used up and you can't thread the cap nut in anymore. In this situation you need to back the packing nut out all the way, take a fresh piece of flax rope and wrap it around the shaft and then put the cap nut back on.

By the way, this is the exact same procedure that you would use to fix a garden faucet that leaks out the valve stem when the valve is open. Unthread the cap, wrap the packing string around the valve stem, thread the cap back on. You can even do it with water pressure on.

As for the shop quote: did they know the boat was all torn apart when they quoted you? I can bet getting that gas tank out was not an easy operation....

Thanks guys for the input, I really appreciate it. As far as shops go, I've given up which is why I am trending towards doing the work myself. I do my cars, and the boat engine is more accessible, so...Anyways, it seems that all the shops here in SoCal are expensive...ridiculously so, and there are very few. The others are basically auto mechanics that say they work on boats. I took my last boat to one of those guys and they replaced the fuel line with automotive stuff.
I removed the gas tank because it was old plastic and was sagging pretty bad, and looked like someone microwaved it...But yes it was a bitch to get out, especially since it was full--I need to plan my work better! I'm replacing it with a new aluminum one that will straddle the rudder on mounts that will have easier removability so I can service the rudder in the future if necessary. Also, I'm taking the time to include a water separating fuel filter near the tank since there will be room.

I'm still confused about the rubber hose here. The "stuffing" is placed between the shaft and the threaded tube, right? The gland nut then threads onto the tube to compress the stuffing. Where does the hose fit into the loop?

CRS:
The rubber hose is just to provide a degree of flexibility to the system. Referencing your picture:

On the left is the thur-hull fitting that is essentially glassed into the boat. The tube that passes through the boat would end just to the right of the left most hose clamp. There will be a gap between the two hose clamps that will allow the hose to flex a little bit, then the rest of the thru-hull continues.

Just to the right of the hose clamp is the flange from the tube that the hose is clamped to. The threads that you see are a part of this fitting. Continuing to the right is the "thin" lock nut that I mentioned. To adjust the packing you would turn the lock nut so that it moved to the left, thus "unlocking" the gland nut. Note that you will need to holt the gland nut still while you turn the lock nut.

To replace the packing you would turn the gland nut so that it moved to the right. It may have to turn a fair amount as it could have an inch or so of threads in there. The old packing will probably be packed into the "cap" of the gland nut. You may want to pick it out so that you have a clean start, or you can just add some more to that is there.

The "flax" packing comes in a variety of different sizes. What you want is to get some flax that is just a little smaller in diameter than the gap between the shaft and the inside diameter of the gland nut. Wrap a length around the shaft, cut it so that the ends will just meet and then thread the gland nut back on.

I would tighten the gland nut down until it was "firm" so that it compressed the flax, then back it off until it was just "snug". When you launch the boat next time, adjust the gland nut so that the shaft does leak a small amount when you are running but slows or stops when the shaft is not turning. Tighten the lock nut against the gland nut to make sure it doen't loosen up.

Awesome, thanks for all the info. Now it really doesn't seem to be all that foreign.

Damn Rod,
If only my Chilton manuals were that clear, detailed, and precise. I might get my projects done right the first time. Nice!