Rebuilding Sherwood G65 for Perkins 4-108

[jfhspike]

Originally Posted by jfhspike

I meant to also say: the Erving seal is 1/4" thick, but the SKF one is 3/8" thick. But that's OK, because the socket you press it into is 3/8 deep, so it fits fine.

And last but by no means least --- the SKF one has a steel shell, and WILL corrode. But it may get you home as long as the trip takes no more than a week or so.

I'm still seeking a stainless-shell equivalent, but have yet to locate one, alas.

[sharkdiver84]

I know this is an old post and I probably won't get any replies, but let's try. I've got the same problem on my F-85 which is more or less the same pump, same rebuild kit and everything. Same bearing corrosion, same stuck ring from the lip seal. Trying to bang out the ring has been futile. It just bent and now I can drive the socket through to no effect. It seems like I'm screwed. Cutting it out with a Dremel seems highly risky because a slight error will damage the seat if the seal. Any suggestions, besides buying a new pump? I actually already did that, but got cheap, and now it doesn't fit without installing an adapter plate.

[jfhspike]

Originally Posted by sharkdiver84

I know this is an old post and I probably won't get any replies, but let's try. I've got the same problem on my F-85 which is more or less the same pump, same rebuild kit and everything. Same bearing corrosion, same stuck ring from the lip seal. Trying to bang out the ring has been futile. It just bent and now I can drive the socket through to no effect. It seems like I'm screwed. Cutting it out with a Dremel seems highly risky because a slight error will damage the seat if the seal. Any suggestions, besides buying a new pump? I actually already did that, but got cheap, and now it doesn't fit without installing an adapter plate.

You might try heat and cold: warm up the pump body in the oven, and then holding it with a potholder, put an ice cube on what's left of the lip-seal body. The main thing this does is possibly provide some relative motion of the two breaking any bonds that have happened in there, After that, you might be able to grab some corner of the seal with needlenose and start it moving.

But your worry about the dremel may be excessive: if you cut through the metal case of the seal and cut into the bronze body a little, it's not the end of the world! When you install the new seal, you put some goop on it, and that will fill the space between the pump body and the seal (and will mostly squeeze out, because there's really almost no space there). Don't use 5200 --- go with something like permatex #2. The only critical part you don't want to scratch is the shaft itself, because the seal rides on it, and an axial groove in the shaft could chew up the seal fast. But on the OUTSIDE of the seal? That's static, and goop will do wonders. Work the dremel very gently so that you don't cut a deep groove, and keep a vacuum or blower on the area while you do so, so that you can detect the moment you see bronze color rather than bearing-shell color and stop!

Best of luck. Once you get a complete slit in the bearing shell**, the whole thing should pop out easily

--John

** All the way from "near the place where the seal rode on the shaft" out to the outer surface, and then all the way up that outer surface to that the shell is now a "C" shape rather than an "O" shape, with the "gap" in the "C" being about 1/32 of an inch or whatever you managed with the dremel.

[sharkdiver84]

Thank you. That all sounds doable. I wasn't aware of the goo. I thought you pressed in the new seal. Worries me that if done if it should over it would create an obstruction for the impeller, but I guess I could just remove that before it cures. Is that standard procedure, or just a fix in case I knick the bronze?

[jfhspike]

Permatex number 2 has been used for years to deal with nicks and scratches of various sorts in low-pressure situations.

The seal IS a press-fit, so you'll need very little goo, and mostly it'll squeeze out, and you can wipe it up with a paper towel. You can make it even cleaner if you put a tiny bit of alcohol on the towel (I think that's the solvent that works...you might want to try a little first).

[sharkdiver84]

Got the job done with a Dremel and a little help from the screwdriver. Couldn't get a cut off wheel positioned right, so I resorted to grinding with the pointy grinder bit. That left a small circular depression in the outer edge of the seat. Also a handful of gouges from trying to pry it out with a screwdriver initially. Even a noticable bump on the bottom of the housing where the impeller sits, that I suppose I can grind smooth.

There's also a lot of rust corrosion bonded to the seat both sides from the rusted out bearings. It would be easy to remove with a wire brush but the Dremel brush will scratch it and my hand held bronze it too large to fit.

The fate of my boat is riding on this project as I have to move it ASAP. At this point would you cut your losses and go with the new pump, or continue with the rebuild, putting faith in the gasket goop? Money is tight, especially since I keep discovering new problems. Am I likely to encounter trouble getting it to all go together? The kit comes with pre pressed bearings on a shaft as well as the seal, gaskets, impeller, everything but the body.

[GrowleyMonster]

Glad I found this thread. I just got a brand new Sherwood G65 for my Westerbeast and I figure on rebuilding the old one if it looks like it needs it, otherwise just service it with new impeller and cam, while it is off the engine, so it will serve as a ready spare.