sherwood / oberdorfer water pumps

[Tom Glennon]

Gentlemen: my lovely vintage '87 yacht has an M25XP with a Sherwood raw water pump.

While perusing a publication, I came across an interesting article that described a particular kind of "weeping" that is common on Sherwood pumps when it is time for them to be rebuilt.  I do believe I am a candidate for rebuilding, and I am curious if the Oberdorfer pump is a direct swap-out for the Sherwood, and also would like any feed back as to weather one is perferred over the other. This will be another of my winter projects!

Thanks, and Happy Thanksgiving to all!

[Ron Hill]

Tom :  No the Oberdoffer is not a direct change out.  As I recall you (might!!) have to get shorter threaded studs that go into the engine. 
I know that when you go from a Oberdoffer to a Sherwood you need to get longer studs.  Maybe the longer studs will work?? 

[td]

I have hull #543 and have done the Sherwood to Oberdorfer replacement.  It was direct, that is; disconnected the hoses, unbolted the Sherwood, bolted on the Oerdorfer, and connected the hoses.  Everything fit.

However, the PO did the original conversion in the other direction so I do not know what, if any, modifications he made to make it work.

I think the Oberdorfer has a little less capacity than the Sherwood but I am not sure. After the exchange the engine seemed to run a few degrees warmer in the summer.  Perhaps 164 degrees verses 161 degrees but this difference could have many other causes.

[captran]

I  have a 97 which I switched over.  I needed a few brass fittings to make the switch which were available in a Spanish Wells  (Bahamas) hardware store for a couple of bucks.  Don't recall the size off the top of my head.

[Tom Glennon]

Thank you gentlemen for your replys... I did remove the pump over the weekend, and all looked normal on the interior, i.e. no signes of water intrusion... but the evidence of salt water on the block leads me to believe the pump is in the first stages of failing, so I will now investigate the rebuilding process.  Not sure of any special tools involved, but I do enjoy tearing things apart and putting them back together... great way to understand the intricacies of all the mechanical parts!

Happy Turkey Day to all!

[Stu Jackson]

Tom

The carbon seals are what gives out.  They "look" OK, but have worn, and that's why water and oil can be getting by.  Nigel Calder has a good description of how to replace the bearings with "homemade tools" in his Boatowner's Manual for Mechanical & Electrical Systems.  My Universal dealer wanted to charge almost as much as a new pump to redo the bearings on my old pump! in 1999.  I bought a new pump and keep the old one, although when this (new) one goes, I'll probably just get another.  My experience was that the bolts holding the pump onto the engine were a real weak point.  It took me two days to get them off before I learned about PB Blaster in lieu of liquid wrench.  I used nylock nuts on the pump.  We have an Oberdorfer.  From reading past posts, it seems the Oberdorfer is much easier to service the immpeller since the cover screws are in the front.  The pumps do almost the same work, so there's really no difference between them.

[Jim Price]

Has any one had any experience with the "universal replacement cover" that uses thumb screws on the front to mount? 

I cannot remember the brand name but remember the item supposedly uses a configuration that allows hand removal of the cover (it swings out of the way by removing or loosening only couple of screw bolts) for impeller replacement / inspection.  Supposedly solves the issue with Sherwood reverse bolts.

I would welcome any experiece and would really appreciate the darn name!  Getting old is for the young!!

[Ron Hill]

The Sherwood raw water pump does pump more water thru the heat exchange, than the Oberdofer pump.  I don't know the exact amount, but I'm sure it'd only about 10% or less.  (more impeller blades and a slightly larger chamber)
Both pumps have lip seals that hold the oil in the engine or the water in the pump.  These lip seals wear and the shaft they ride on wears. The carbon bushing only acts as a "spacer" to hold the shaft connecting the impeller to the engine connection, centered. (very little wear)
I've found that the Oberdofer is all non rusting metal, where as the Sherwood pump has some "ferris" parts.  Some owners may have replaced some of the mounting hardware ie nut/bolts, with "ferris" items that will rust.  
You can get a discount on the entire or parts of the Oberdofer, but the Sherwood is $$ with NO discount !!  

[Steve Hansen]

Hey Jim,

I was looking at speedseal too. $58 at this web sight http://www.speedseal.com, and $78 at Torrenson. I'll probably go with the Globe impeller also (supposed to be more durable)

Steve

[Gary Ambrose]

Interesting and helpful thread.  Thank you to all!  Can anyone profide a source/link;  and best price on a Oberdorfer Replacement Pump?

Thanks again.

[Jim Price]

Thanks Steve for the name.      I tried every combinations of names on internet search and just could not get a hit.

I am, and I would bet others are interested in some experienced feedback on success for failure of the Speedseal.  If anyone knows of an application out there, let us know. 

I don't want to switch to something that might cause catastrophic failure down the road.

[Ron Hill]

Gary : There have been a number of posts on this topic and where to get the best price.  The company is called DEPCO and I listed that 800 telephone number in those posts.  Traveling and I don't have that # handy.   

[karista]

I bought a new Sherwood pump from www.Depcopumps.com, they also rebuild my old Sherwood pump for about $100, the shaft was grooved and needed replacement. I now have the old rebuild pump as a spare.
Bernd Mueller

[Rick Johnson]

Try depcopump.com

[Tom Glennon]

You guys are sharp! I was going to bring up the subject of the Speed Seal cover, and you beat me to it!  My neighbor and sailing friend introduced me to the Speed Seal cover after I had to make an "emergency impellor change" this past season.  Simply designed, and with the way it is designed, foolproof as well! He swears by it.  I will be ordering mine over the winter.