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Go Back   WakeWorld > >> Boats, Accessories & Tow Vehicles Archive > Archive through September 10, 2007

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Old     (wkbrdindmax)      Join Date: Jul 2004       08-15-2007, 3:53 PM Reply   
Our '94 MC Maristar is taking on water around where the drive shaft enters the hull. Being a V Drive, its almost impossible to see why it is doing this. It takes on water quite rapidly. Does anyone know what is going on, or have any words of advice on how one might go about fixing that? Let me know, thanks in advance.
Old     (phatboypimp)      Join Date: Apr 2005       08-15-2007, 3:58 PM Reply   
There is a large nut where the shaft of your boat nears the hull. Inside of that nut is a waxed rope called packing. Over time that wax rope wears out, you need to take the nut apart and replace the packing. Pay careful attention to the directions on the packing as you should have a "drip rate" which allows some dripping to occur which helps to lubricate the shaft during operation.

This is an easy fix and should be a part of regular maintenance for your boat.
Old     (wkbrdindmax)      Join Date: Jul 2004       08-15-2007, 4:19 PM Reply   
Jason, thanks for the quick reply. The only problem is that my boat doesn't have any nut on the shaft near the hull. Infact, above the propeller there is nothing on the shaft at all up to where it enters the hull. My boat is the 225VRS so it is a V Drive. Would this nut be located somewhere else inside of the hull? Please tell me it isn't under the engine!! Anyway, thanks again to all who help me.
Old     (slideinsidwayz)      Join Date: Jul 2006       08-15-2007, 4:38 PM Reply   
Yes @ the coupler!!!!!!!
Old     (phatboypimp)      Join Date: Apr 2005       08-15-2007, 4:41 PM Reply   
Sorry Bobby, it is in the engine compartment, where the shaft enters the hull. Mine is a direct drive, so maybe a v-drive owner can be more specific on what to look for.
Old     (wkbrdindmax)      Join Date: Jul 2004       08-15-2007, 4:48 PM Reply   
Andrew, are you saying yes to under the engine? Any easy way to fix this without pulling the LS1 out?

Jason, thanks for the help.

Anyone have any ideas?
Old     (slideinsidwayz)      Join Date: Jul 2006       08-15-2007, 5:33 PM Reply   
Yes, under motor/ v-drive unit. Easy fix IF you can get to it.!???!
Old     (mobv)      Join Date: Jun 2002       08-15-2007, 5:44 PM Reply   
Replacing packing is one of the hardest maintenance activities on a v-drive, it is under the transmission, often requires a special wrench to fit the nut and have room to move.
Old     (rodmcinnis)      Join Date: Sep 2002       08-15-2007, 5:45 PM Reply   
There are two common seal arrangments for the propshaft on an inboard (either direct or V-drive).

The "old school" is to have an adjustable packing gland. The "flax" is wrapped around the shaft and then compressed with the gland nut. As the packing wears out you simply tighten the gland nut down a little more to compress the flax against the shaft. A Jam nut backs up to the large gland nut to keep it from moving. Ideally, this type of seal SHOULD leak a tiny bit to keep the flax cool and lubricated. A drip every few seconds while running is considered normal.

The other seal arrangement is often referred to as "dripless". This utilizes a rubber ring seal, very similar to what you might find on wheel bearings or engine shafts. When these seals start leaking the only solution is to replace them. The bad news is that if they start leaking it is often because something else went wrong, like a bend prop shaft. While the Flax/stuffing box arrangment is fairly tolerant of misalignments, the seals ("dripless") are not.

On a direct drive the stuffing box is usually in an easy place to get to. On a V-drive it is under the engine. No, you shouldn't have to pull the engine to get to it but you may need to be a contortionist and be able to work by feel. There also won't be much room for tools.

To find the seal, either dripless or stuffing, simply start at your V-drive and follow the shaft down until it gets to the bottom of the boat. Whatever that fitting is that the shaft passes through on its way out the bottom is your shaft seal.

If you have a dripless seal then there will be some sort of seal there to replace. You will need to remove the prop shaft entirely from the boat, pop the old seal out, press the new seal in, replace the prop shaft. I know, a lot easier said than done.

If you have a stuffing box then there will be a very large nut that the prop shaft passes through. Actually two very large nuts. The outer one (the one closes to the V-drive) will be thin, like maybe 3/8". That is the jam nut. That must be loosened first. The Gland nut will next in line, and it will be something like and inch thick. Once the jam nut has been loosened you will want to tighten the gland nut a little bit. How much? Only enough to slow the leak to a drip every few seconds. Do NOT overtighten it!

The jam and gland nuts are very large but they shouldn't be very tight. You probably won't have a wrench that large, and you wouldn't have room under the engine to turn a wrench that large even if you had one. Go to the hardware store, to the plumbing section, and buy one of those wrenches that are made for the drain fittings. You may need two of them, one to hold the gland nut while you turn the jam nut.

If this is the first time you have adjusted the packing then it will probably adjust okay. If it has been adjusted a number of times before and you can't tighten the gland nut down anymore then you need to replace the Flax packing. By the appropriate size (no, I don't know what size it would be....), cut a strip that will wrap around the shaft and have the ends barely touch. (note that you can do this on a section of the shaft you can get to easily, like under the boat...)

Now back off the jam and gland nuts all the way, slide them up the shaft out of the way. Wrap the new flax around the shaft, slide the gland nut over it and thread it down onto the stuffing box. Tighten the gland nut until you get a little bit of resistance. Lock it with the jam nut. Run the boat for a bit, then readjust to get the desired drip rate.

Rod
Old     (wkbrdindmax)      Join Date: Jul 2004       08-15-2007, 6:01 PM Reply   
Thank you all for the help. Rod, thank you for the detailed description. I actually have some understanding of what you are talking about, and being one who isn't real mechanically inclined, that is saying something. I'm going to look over the boat in the places you've mentioned, try to determine whether or not I can get to the right area, and which version of seal arrangement I have. I'll keep you all posted. Thanks again so much for all your assistance. Thank goodness for Wakeworld.
Old     (wkbrdindmax)      Join Date: Jul 2004       08-15-2007, 6:05 PM Reply   
Slightly unrelated, but what is the small grate with some sort of whole behind it located just ahead and left of the prop shaft? I hadn't noticed it before, but judging by the stain water was been dripping out of that location as well for awhile.
Old     (zo1)      Join Date: Aug 2002       08-15-2007, 6:09 PM Reply   
Bobby that sounds like your scupper for your fresh water intake. That is where your engine gets its cooling water from...

If you have two of them the other is your ballast intake...
Old     (wkbrdindmax)      Join Date: Jul 2004       08-15-2007, 10:42 PM Reply   
Ok, we went for a little test and tune session, and I couldn't fix it. Here is the current situation.

First, I found the area in question. Under the rear wide passenger cushion, I can access the shaft where it exits the hull. The nuts and the seal area appears to be ok, as there is no water leakage. The leakage is coming from the very rear of that assembly, where the long rubber gasket slides up and over the ring surround the shaft as it leaves (sorry for all the technical words...haha). Fabric which I assume is packing appears to be coming out from inside and is plastered all over the compartment.

Any ideas from my poor description?
Old     (chaser)      Join Date: Sep 2006       08-16-2007, 7:19 AM Reply   
if you got a digital camera, snap a photo and post it.
Old     (mobv)      Join Date: Jun 2002       08-16-2007, 7:55 AM Reply   
Bobby that is the packing assembly, you will probably need to add some packing rings. There have been some detail postings on how too in the past.
Old     (olskooltige)      Join Date: Mar 2007       08-16-2007, 8:34 AM Reply   
There are tutorials on installing both at wakeboatworld. Pics included of different types (nylon and brass nuts), no v-drives though. If someone wants to send me some pics of v-drive packing setups, I'll be more than happy to post them in the article.

Bobby, take a look at the photos in these articles, and it may help you out.

Rope packing
http://www.wakeboatworld.com/index.php?option=com_content&task=view&id=22&Itemi d=35

PSS install
http://www.wakeboatworld.com/index.php?option=com_content&task=view&id=24&Itemi d=35

(Message edited by olskooltige on August 16, 2007)
Old     (ottog1979)      Join Date: Apr 2007       08-16-2007, 12:29 PM Reply   
I recently adjusted my stuffing box. It was much easier than I expected. You just need two big wrenches.

Another article on adjusting:

Servicing Your Stuffing Box

by Don Casey

If your boat has inboard power, odds are it is fitted with a stuffing box to provide a watertight seal for the propeller shaft. Stuffing boxes are also used to seal rudder stocks that penetrate the hull below the waterline.


In principle a stuffing box is identical to the packing nut on a common faucet. Its primary components are a threaded sleeve and a hollow nut through which the shaft passes. The sleeve - or sometimes the nut - is filled with rings of braided square flax rope that has been heavily impregnated with wax and lubricants. Tightening the nut compresses this packing against the shaft, forming a watertight seal while still allowing the shaft to turn.

Adjusting
Water is required to lubricate conventional packing, so a properly adjusted stuffing box can be watertight when the shaft is stopped, but it must drip when the shaft is turning. Two or three drops per minute are adequate. It is not uncommon to see stuffing boxes leak at a much higher rate. This doesn't harm the shaft or the stuffing box, but the spinning shaft will sling this excess flow all over the engine compartment, leading to rampant corrosion of the shaft coupling, the transmission housing, and everything else getting sprayed. Even more disastrous, it puts an unattended boat at risk of sinking. If your stuffing box leaks more than 8 or 10 drops a minute, it needs servicing. Tightening the stuffing box nut a half turn is all that is required to reduce the leak, but the location of the stuffing box can render this job far more difficult than it should be. Access can be especially challenging in boats with V-drives and in sailboats.


The first step in stuffing box adjustment, then, is to figure out how to get two wrenches on the box--one for the lock nut and one for the adjusting nut--and how to position yourself so that you can pull on one while pushing on the other, and vice versa. You can use pipe wrenches to turn the nuts, but adjustable packing nut wrenches tend to be easier to handle in confined spaces. If the stuffing box is above a deep bilge, tie a retaining line to the wrenches before you start. With your wrenches on both nuts, hold the adjusting nut and turn the locknut clockwise to release it. Back this nut off a couple of turns. Now turn the adjusting nut clockwise until the dripping just stops.

CAUTION: Some stuffing boxes are rigidly attached to the hull, but most are connected to the shaft tube with a length of flexible hose. You do not want to twist this hose or twist the stuffing box inside the hose. If the adjusting nut does not turn easily, use a pipe wrench on the stuffing box flange--located just forward of the hose--to keep the box from turning with the nut. If the box is corroded, back off the adjusting nut several turns and wire brush the box threads bright before making the adjustment. Give threads and nuts a heavy coat of Boeshield T-9 (or some other corrosion blocker) to avoid this problem in the future.

After you make this initial adjustment, you are going to need to check the drip rate with the shaft turning. You can do this either with the boat underway or with the transmission engaged in forward and the boat securely tied in the slip. With the help of a flashlight--and a mirror if you need one--count the drops per minute. If it is more than two, tighten the adjusting nut slightly. If you cannot make this adjustment without putting body parts or clothing in dangerous proximity to the spinning shaft, stop the engine, make the adjustment, then restart it to check the drips. When the drip rate is one or two drops per minute, stop the engine. Hold the adjusting nut securely so that you do not alter the setting, then tighten the locknut against it. Before you extract yourself from your access position, carefully check the strap clamps that attach the hose to the stuffing box and to the stern tube. These inevitably corrode at the bottom, so you may need a mirror to check them. Better yet, release each one and rotate it to view all sides before retightening. Do this one clamp at a time.

Repacking
After the packing nut has been tightened a few times, the packing gets so compressed that it becomes hard enough to actually wear a groove in the shaft--a condition you want to avoid. In a powerboat used regularly, the shaft packing should be replaced at least every other year. Sailboats may not need to have the packing replaced for five years or more, but when the stuffing box starts requiring frequent adjustment or if it begins to feel warm, it's time.


Repacking is straightforward. Hold the packing nut while you release the lock nut, then unscrew the adjusting nut completely to open the box. You must dig out ALL of the old packing. The easiest way to do this is with a corkscrew-like pick designed specifically for this task, but a sharpened piece of stiff wire bent 90 degrees at the end will also do the job. Take care not to scratch the shaft with either tool.


If the old packing comes out relatively intact, use it to determine what size packing you need. If it comes out as shapeless wads of fluff, then measure the space between the shaft and the inside of the packing nut to determine the correct flax size. Multiply the diameter of your shaft by 14 to get the approximate number of inches you need for 4 layers of new packing--usually sufficient.


A common mistake is winding the new packing around the shaft as a continuous piece. Packing installed this way will not seal properly. It must instead be installed as a series of stacked rings. This requires cutting the packing into lengths that just encircle the shaft with ends touching. The easy way to do this is to wrap the packing around the shaft in some accessible location and cut across the overlap with a razor knife. Curl one of your cut lengths into a ring around the shaft and push it into the stuffing box. Tamp it evenly with a small dowel or a blunt screwdriver to push it all the way to the bottom of the box. Push a second ring into the stuffing box on top of the first one, staggering the joint about 120 degrees. Add a third layer, then a fourth, each time staggering the joint. If you don't seem to have room for the fourth layer, hand tighten the adjusting nut to force the other rings deeper, then remove it again to see if this made room for an additional ring of flax. When the box is full--but not so full that the adjusting nut doesn't thread on easily--adjust it to drip two or three times per minute, as previously outlined. You will need to check this setting after the first couple of hours of use; some tightening is usually required.

Because you remove the old packing before installing new, and it is the packing that is keeping the ocean out of your boat, it should be out of the water when you do this job. If you must do it with the boat afloat, have the new packing ready to install as soon as the old is out, and drape a towel over the stuffing box to deflect the incoming flood into the bilge, where your bilge pump should handle it without difficulty. You can make the task less frantic by sealing the shaft from the outside with plumbers putty, but you will have to go into the water twice to do this, once to put the putty around the shaft, and a second time to remove it. Do not turn the shaft while the putty is in place or you will break its seal, and make sure you clean out ALL the putty when you are finished since both the stern bearing and the shaft seal depend on water flow for lubrication.

Drip-Less Packing
An alternative to conventional braided packing is Drip-Less moldable packing. The advantage of this type of packing is that it is self lubricating, which eliminates the necessity of letting the stuffing box drip. Drip-Less packing requires two retainer rings of conventional packing. You install a ring of conventional packing, then push Dripless Packing into the box until it is about three-quarters full. A second ring of conventional packing completes the job. Tighten the nut just enough to stop the box from dripping. This type of packing runs hotter than water-lubricated flax, and over tightening will generate excessive heat. The stuffing box should not be too hot to touch. Low-friction packing is six to ten times more expensive than flax, but because it rarely needs adjustment, it can be a good choice for a stuffing box that is particularly difficult to service.

For more information about boat maintenance, consult This Old Boat by Don Casey
Old     (laraujo)      Join Date: Apr 2007       08-16-2007, 1:38 PM Reply   
I have the rope packing nut on my DD. When I was talking to my dealer about an alternative he said that there was a dripless type that I think plumbed in water pumped from the engine to cool the fitting. Has anyone got something like this.
Old     (olskooltige)      Join Date: Mar 2007       08-16-2007, 3:21 PM Reply   
There are 2 types of dripless. One is a gor-tex fiber impregnated rope that installs just like a regular packing, but isn't that dripless. The other uses what you see in jet skis and newer boats, stainless collar against a carbon flange, and is truly dripless. If you look at the 2 links I posted 2 post up, you can see both types. There is also a goo you can pack in them, but that is not recommended.

(Message edited by olskooltige on August 16, 2007)

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