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Raw water pump wobble
Posted: Tue Nov 06, 2012 12:09 pm
by srokag44
I noticed that the pulley on my Sherwood E35 raw water pump will intermittently wobble. It will run true for a few seconds and then wobble for a few seconds. I removed the pump, checked the impeller, and reinstalled the pump and belt. I didn't see anything wrong with the impeller or pulley.
My first guess is that the bearing is shot... does anyone have any other thoughts? Anyone have experience with the "major rebuild" kit? Would it be wiser to just spend the extra money and replace the entire pump with a new one?
Thanks!

Posted: Tue Nov 06, 2012 12:31 pm
by P-Dogg
From the picture, the belt looks loose -- the lower section looks to have a curve in it. I'd start by making sure everything is tight and snug if you haven't already. If the bearing is bad, it will be bad all of the time. A harmonic set-up by loose components would wobble when the natural frequencies were right, then stop when they weren't. I presume that you tried wiggling the pulley by to see if it is loose on the shaft or the mount? If not, try that. You can squirt a little oil or water on crevices where parts meet in order to highlight movement. If there is motion between the two parts, the water/oil will squeeze in and out as you rock it.
I presume also that that black powder on the stringer is rubber from the belt and not bearing wear metals?
And you should also ask Santa to get you some all-stainless hose clamps for Christmas!
Posted: Tue Nov 06, 2012 1:24 pm
by prowlersfish
As P-dogg said Belt looks lose . But a bad bearing could cause your issue .
Posted: Tue Nov 06, 2012 1:38 pm
by srokag44
I'll try putting some more tension on the belt tonight and see if that alleviates the problem and I'll double check to make sure everything is good and tight.
thanks!
Posted: Tue Nov 06, 2012 2:30 pm
by Stripermann2
Tighten that belt. It'll slip then grab, this is perhaps when you see the wobble...If the pump seal isn't leaking and even if there is a slight run out of the pulley, I wouldn't worry too much.
Usually the bearing fails, damaging the seal, the leak is the tell-tale of pump failure.
Posted: Tue Nov 06, 2012 8:18 pm
by srokag44
The pulley and shaft seemed to wiggle inside the pump housing and everything else seemed secured so I pulled the pump back out. With the impeller removed there is a great deal of play in the shaft. Should the shaft be pretty constrained in the housing without the impeller in?
Posted: Wed Nov 07, 2012 9:18 pm
by Big D
There should be no play, rebuild her. Jamie is right about the seal but it may not have been bad enough long enough to cause that yet.
Posted: Thu Nov 08, 2012 3:28 pm
by srokag44
Took apart the pump today and found some interesting things. I found no inner race to the bearing, no cage, and only 1 ball. The seal assembly didn't look too bad. I included a picture below of the ball and the seal parts. The outer race of the bearing is completely corroded and stuck in the housing (second picture). The retaining ring that holds the bearing in snapped when I tried to remove it. My plan is to spend some time getting the outer race and the retaining ring out and then decide whether the housing is worth re-using or if I should just buy a whole new pump.

Posted: Thu Nov 08, 2012 4:21 pm
by BobCT
I have a good used one if you want to replace it. Just selling my other spare to another member this week.
Bob
Posted: Thu Nov 08, 2012 7:51 pm
by larryeddington
Can't really tell exactly what is inside but you should be able to get the circlip ring out and press the race out, clean up and put in new bearinge, I said "should" no guarantee. These pumps are made to be rebuilable. Get the brand of the pump and look up an exploded view. I would bet it can be rebuilt a lot cheaper than a new one.

Posted: Thu Nov 08, 2012 10:07 pm
by Big D
When ever I am about to disassemble something that rusty, I throw it into a pail with enough diesel in it to cover the opject and leave it there for a few days prior to taking it apart.
Posted: Fri Nov 09, 2012 5:48 am
by Allen Sr
You may laugh but if you want the rust 'ate' off....... soak it in vinegar. It will eat the rust off and not hurt the metal. Have done it many times. When my son was young he used to get into my tools and leave them out and they would rust up bad and my wife cleaned the rust off with this method.
Posted: Fri Nov 09, 2012 9:06 am
by srokag44
Unfortunately the outer race of the bearing doesn't want to come out after the retaining ring was removed. It is in a blind hole so there is no way to push it out from the back side. Normally it would come out with the rest of the bearing but since there was only 1 ball left, the inner race just slid right out of it.
http://www.sherwoodpumps.com/FileAttach ... PG_E35.pdf
I'll be throwing it in a mill later today and machining the outer race out. I'm guessing it will crack and crumble out pretty easily.
The shaft, housing, and cover don't look worn too badly so I'm going to try to rebuild it. Major rebuild kit for about $120 versus new pump for about $400. Definitely worth the time, especially since I will be rebuilding the other engines pump now that I have seen how bad this one was.