Rebuilding Sherwod Raw Water Pump

[Bob4203]

I ran a thread here several months ago about my Sherwood Raw Water pump weeping droplets of water (intermittent) from a small weep hole behind the impellor housing. From my discussions with several diesel mechanics (marine) its the bearing behind the impellor or the shaft itself. I was told to "watch it" as the probability of water entering the engine through the oil seal is fairly remote. "Once it becomes more steady, rebuild the pump". I plan not to wait for that day, so I will rebuild. Replacing the Sherwood is costly so replacing the shaft and bearing would be more cost effective.

I have the M-18 2-cylinder Universal engine.

Has anyone ever tackled this project? I do not know if a press is required for the bearing or if special tool(s) are need to remove the shaft. I want to explore the "do's and dont's" of this task, so I thought I would ask my fellow Catalina owners to share any experiences with this.

Thanks
Bob
'99 Mark II
Lake Lanier, GA

 

[Bob S]

Bob,
Get rid of it and buy an Oberdorfer. The bodies on the Sherwood are steel and prone to rusting. The Oberdorfer are bronze. I did this a few years ago. Thomas on the C30 yahoo group just recently did it on the same engine. Depco Pump out of Florida sells them and also repairs the Sherwood if you want to keep it as a back up. When I removed mine it just fell apart it was so bad. Wasn't worth the effort to rebuild. This is the one I used:
http://www.adiesel.com/store/OB-N202M-15.html

 

[Bob4203]

Many thanks Bob,

Many others have made the same recommendation. Given I am in fresh water, the Sherwood has no shown any signs of corrosiion of course. The engine only has 525 hours or so. Going online and checking prices the model you referred to is going for as low as $202.30!!

WOW

Do you know if this model is a direct fit (shaft wiidth, bolt hole alignment for the engine block, etc?).

Bob
'88 Mark II

 

[JK_Boston_Catalina310]

Many thanks Bob,

Many others have made the same recommendation. Given I am in fresh water, the Sherwood has no shown any signs of corrosiion of course. The engine only has 525 hours or so. Going online and checking prices the model you referred to is going for as low as $202.30!!

WOW

Do you know if this model is a direct fit (shaft wiidth, bolt hole alignment for the engine block, etc?).

Bob
'88 Mark II

Yes, it should be a direct fit replacement. If you have to modify it, that isn't too bad. I did it on my M-25XPB.

If you still want to rebuild, MaineSail has already answered all your questions on that process. http://www.pbase.com/mainecruising/raw_water_pump

Good luck and fair winds,

Jesse

 

[Bob4203]

Thanks Jesse,

I am not sure what the cost of the rebuilding kit is, but considering my time and a few needed tools to rebuild the Sherwood, the Oberdorfer may be the ticket, especially if I do not need to modify the pump. I will have to reconfigure my hoses but that is okay with me.

Appreciate the feedback everyone.

Bob
"Breezin II"

 

[Stu Jackson]

Here's an Oberdorfer rebuild: http://c34.org/bbs/index.php?topic=6766.0

and http://www.c34.org/wiki/index.php?title=Replacing_a_Sherwood_Water_Pump_with_an_Oberdorfer It includes a discussion of the limitations of the Sherwoods.

Call Depco (www.depcopump.com).

The 202M-15 Oberdorfer is a direct slap in replacement on an M25-series engine for the Sherwood but doesn't need the outside clamps.

 

[Bob4203]

Thanks Stu.........

Good stuff.


Bob _/)

 

[dtedesco]

Here's my experience. Soon after purchasing my Catalina 30, the Oberdorfer raw water pump started dripping. When I arrived a week later to pick up my rebuilt pump, the mechanic showed me a box of worn parts, and a shiny new Sherwood retrofit kit. He said he was saving me $70 by going with the Sherwood, which is just as good. It was easy to retrofit it, and has worked fine in a salt water environment for about 7 or 8 years now.

Funny thing is that after I bought the boat, a couple of people who knew the boat told me that the previous owner had overheating problems. I have never had an overheating problem with the Sherwood pump, and we go on annual cruises with our sailing club of at least 200 nautical miles over a 2 week period.

Best of luck!

 

[Bob4203]

When looking at the cost of a rebuild kit and the time to rebuild for the Sherwood the price of a new Ober. pump outweighs everything as a direct replacement. I have nothing against the Sherwood as my boat has always been in fresh water. Its strictly a cost savings issue for me. I was uinder the impression at first that these pumps were pushing into the $500 range, but I was mistaken as I just saw a new Ober. go for #195.00!

Thanks
Bob

 

[Loubert]

I just replaced my leaking (oil and water) Sherwood yesterday with an Oberdorfer. I had the Sherwood rebuilt by Depco before last season for about $150 including all shipping charges. First time out this year I noticed water coming out the weep hole. Depco said it could happen very easily if you get a little sand in the pump.

Anyway, I ordered the replacement Oberdorfer for not much more money and installation was simple - a drop in replacement. Now I will try to rebuild the Sherwood myself and have it for a backup. Hopefully I will never need it.

 

[Bob4203]

Thanks Loubert,

Just what I was thinking as well. The Oberdorfer seems to be more popular then the Sherwood and for good reasons. It sounds like the cost of a rebuild on the Sherwood comes close to a new Oberdorfer!

Bob
1988 Mark II