is there such a thing as a permanent impeller?

[wumhenry]

If so, I hope I've got one on my 1981 vintage Universal 5416, because I don't know how to get to it. Instead of a screwed-on or bolted-on coverplate, the seawater pump cover seems to be mounted on 3 pins that are slightly recessed in their holes. Should I try to pry it off with a screwdriver? If I did that, would it fit tight enough when I replaced it to keep from leaking? FWIW, the housing says "SHERWOOD" on it.

(No, I haven't run it for 26 years without changing the impeller. I bought the boat last July. The guy I bought it from can't answer the question because he had all engine maintenance done professionally.)

[camaraderie]

Just guessing...but could those 3 pins be the end of bolts that are accessed from the other side of the impeller pump?
Here's a link to the guys who make Sherwood.
Marine-OEM - Sea Water Pumps - Summary

[Maine Sail]

You actually access the screws from the back side and need to remove the pump from the engine to change the impeller. While your at it you can replace the pumps shaft seals..

[wumhenry]

Originally Posted by halekai36

You actually access the screws from the back side and need to remove the pump from the engine to change the impeller. While your at it you can replace the pumps shaft seals..

Oh. thx
I hope they're bolts; I don't think there's enough room for a screwdriver between the back side of the pump and the engine block.

[Freesail99]

I have a flex screwdriver in my tool box. It is a handle with a spring like shaft which can be bent to fit most areas. Comes in handy at times.

[tommyt]

I have a newer Sherwood on my 2004 C34. They have probably not changed the design. They are bolts, I think 7/16, and you access them with a small wrench from behind. Best done with a very cool engine and someone with small hands. Getting it off is easier than getting the bolts back in the holes, aligned, and threaded without stripping the bronze threads. Just found this week, unfortunately, that if you do strip the threads that the bolt only goes half way thru the cover. Get a longer bolt and use the threads that have never been touched before.

I inquired about switching to a quick cover that I have heard mentioned on this site. I was told that I could certainly do that, but I would need a different water pump, because it cannot be done on the Sherwood. So, if you have an impeller problem and need to move quickly, better be able to sail out of trouble. This is not the fastest fix in the world. A two bloody knuckle fix for my fat hands.

[hellosailor]

Tommy, I'd suggest taking the pump to a local machine shop while it is off the engine. It sounds (he rashly said) like any decent machinist could fit you with some different bolts that could be accessed from the outer side, or something similar. Possibly just cutting the bolts short and inserting studs from the outer side--so you could just bolt down the cover from the outside or use wing nuts on it. (There's pros and cons to wing nuts, they are also better at loosening themselves.)

But any decent machine shop will eyeball it for you for free.

[Quickstep192]

When you finally get in there, you may want to consider one of these. They are supposed to be able to take more abuse than regular impellers.

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Just in case that link doesn't work, Google "Globe Impeller"

[sailingdog]

I'd second getting a Globe Impeller. It sounds like you have one of those wonderful designs that require you to remove the water pump—just to change the impeller. Obviously, designed by a mechanical idiot, since changing the impeller is a fairly routine task, and forcing the person to remove the entire water pump is a really stupid design IMHO.

As I have said before—"If the engineers who design engines had to work as service mechanics on them for a month, intelligently designed engines would become quite common."

[wumhenry]

Originally Posted by sailingdog

I'd second getting a Globe Impeller. It sounds like you have one of those wonderful designs that require you to remove the water pump—just to change the impeller. Obviously, designed by a mechanical idiot, since changing the impeller is a fairly routine task, and forcing the person to remove the entire water pump is a really stupid design IMHO.

As I have said before—"If the engineers who design engines had to work as service mechanics on them for a month, intelligently designed engines would become quite common."

Yep.
Removing the three bolts holding on the cover with a wrench is well-nigh impossible due to obstructions.
Worse, I found out today that removing the entire pump housing from the block is no picnic, either. After lots of fumbling and straining, I loosened the bolts that go through the flange at the base of the pump housing enough to raise the boltheads at least a quarter of an inch. That didn't loosen the pump housing one single bit. I tried and failed to loosen it by grabbing the housing and trying to pull and twist it. Nothing budged. At that point, I got chicken and tightened the bolts back down. I'm thinking seriously of putting in a work order for replacing the pump with one that has a screw-on cover plate. Anyone know how much $ Sherwood raw-water pump units are selling for nowadays?