Pump Drive

[Paul]

We took our boat out for the first ride of the year yesterday and it ran great. I did however hear some squeaking sound coming from the engine bay but since I planned on replacing the impeller and belts, I didn't give it much thought. The squeeking got louder and apon a closer look seems to be coming from the bearings in the pump drive. I plan on going back tonight to remove the pump and press the bearings out to install new ones.

Has any one else done this and if so is it fairly straight forward or should I be watching for any thing in particular?

[9rock]

We took ourboat out for the first ride of the year yesterday and it ran great. I did however hear some squeaking sound coming from the engine bay but since I planned on replacing the impeller and belts, I didn't give it much thought. The squeeking got louder and apon a closer look seems to be coming from the bearings in the pump drive. I plan on going back tonight to remove the pump and press the bearings out to install naw ones.

Has any one else done this and if so is it fairly straight forward or should I be watching for any thing in particular?

make sure belt is tight

[Paul]

I removed the assembly from the boat, removed the pump housing, impellor and pulley. Now I'm looking at the bearing housing with a seal around the shaft at the pump end and at the other end I see a sealed bearing that simply looks to be pressed in place.

Since I don't see any other retainers or C clips, can I simply press the shaft out of the housing at this point or is there something else that I should know? Will both bearings come out with the shaft?

Any thoughts?

[davidsmith]

I have rebuilt several seawater pumps and they all had a c clip holding the outer bearing in place. (Behind the pulley). I then could press the shaft and bearings out from the impeller side out the drive side. Hope this helps.

[Paul]

Thanks David,

When I looked at the bearing, behind the flange for the pulley, I couldn't see a c clip or a groove for it. It would make sense that there should be one so I'll look again before putting it in the press.

[Boaterguy]

Thanks David,

When I looked at the bearing, behind the flange for the pulley, I couldn't see a c clip or a groove for it. It would make sense that there should be one so I'll look again before putting it in the press.

Does this help?
http://www.sherwoodpumps.com/FileAttach ... 5_TECH.pdf

[k9th]

My Merc 255s had pumps that had no C clip and were notorious for having the shaft "walk" out of the housing when the bearing was failing. I had this happen on my starboard engine last year causing the belt to come off and the engine to over heat. The new design solves that problem so I have replaced both pumps with the new style.

Not sure if yours is the same style but it sounds like it.

[Big D]

I'm sure there must be a way to determine how far to press a bearing back in otherwise the shaft will not sit in its proper place in the housing and there will be a belt alignment issue. Some units have a stop edge machined on the shaft and others use a retaining ring/clip. Probably also have a retaining clip to prevent lateral movement so the bearing doesn't back out either.

[Paul]

Turns out that there was a c clip hidden away behind the front seal. Had to pull the flange off of the end of the shaft first. It has a .002" interferance fit which is tight for a 3/4" shaft. Then by trying to press the shaft out of the housing, the c clip gave just enough to allow the seal to pop partially out. I was then able get a hold of it and knock it out. This exposed the c clip which was now bent but came out easily. To my surprise, the shaft and bearing assembly slipped right out. I measured about .002" clearance between the outer race of the bearing and the inside of the housing. There were however no signs of the outer race spinning inside the housing. The front bearing did show signs of wear and the grease inside of it was pretty gray. Guess I caught it in time.

This pump is similar to what Boaterguy posted however the Merc version of it seems to have fewer parts.

Thanks for the help,