Prop pushes water up through rudder shaft

[Gary H]

Finally started my Yanmar 1GM on a 22D ( after a removal/bebuild/reinstall - new cutlass, new shaft, new engine mounts). I was pleased to see how smoothly it ran and propels the boat with very little vibration. I notice, however, that when the prop is running, water enters the cockpit through the rudder shaft - from under the teak plate. There is no leak when when the prop is not turning. It would seem that the force of the prop is pushing water up the shaft. Any advice on what the fix for this would be.
Gary

[Joe Myerson]

Gary,
The critical question to ask here is how fast were you going (how many rpms was the prop making) when you started to see water come up the rudder tube? I noticed the same thing on my 25D when I run my 1GM at near top rpms. I was assured that this is nothing to worry about, because the water is rushing around and past the rudder at a higher rate than the rudder can deflect. Sure enough, when I motor at lower speeds, or when I'm sailing, there is no water seepage around the base of the tiller.
So, if my informant is correct and you were revving up your engine, you won't see any seepage under normal circumstances.

--Joe

[Brian2]

I don't think you have anything to worry about here. Normal like stated before.

[Gary H]

Thanks Joe and Brian. One less thing to worry about is good news. I think I did have the engine up to 2500 rpm when water started coming up.

Now I can concentrate on adjusting the stuffing box (ugh!) as I don't seem to have a drip. Seems like there's drips where you don't want them and none where you do.

[Oswego John]

Gary,

As Joe stated, watch the RPMs and if possible, do not exceed the point of leaking. A little water entry is no big deal.

Look through the archives. This has been discussed several times through the years.

I have seen guys pack water pump or other heavy grease down into the top of the rudder post's shaft.

If the water entry becomes a problem and you have sufficient room for it, I have seen a flexible Fernco type drain pipe reducer used to check the water's entry. They come in assorted diameters and cost maybe, $3.00/$4.00. The larger end slides over the shaft surrounding the rudder post and the screw clamp is secured. The smaller end of the reducer slides over the narrower rudder post. If the upper end fits snugly, you don't have to tighten the upper clamp. If the upper fit is sloppy, it is okay to tighten the upper clamp a bit to snug things up without creating friction on the post.

The lazy person's way to install a Fernco type reducer is to first slit the entire unit lengthwise and wrap it around the tube and post. Install the lower clamp and tighten it. Adding a bit of caulking and installing the upper clamp is optional.

If working room is tight, the upper end of the fitting can be trimmed down easily with snips or a razor knife. The lower section's main function is to support the fitting in place. The upper section acts as a buffer to prevent water entry into the bilge.

Good luck,
O J

[paul marko]

The way I fixed this problem was to install grease zirk on the shaft just below the tiller head. once a season I put three pumps of water proof grease and voila no leak form the rudder shaft housing. The leak occurs due to the gravitation from the prop.

Paul Marko

ixcatl C/D 28

[rtbates]

While I've never had this happen on our 25D, I've been packing grease around the upper bearing just in case. And for all I know that may be why I've never had water enter there. I just lift the rudder head with the tiller and smear as much grease in the resulting opening that I can. The tiller lifts the rudder head, maybe 1/4".

My guess is that stern squat is the issue, not prop speed. Though they are closely related, haha.