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Nervous about impeller worksterndrive disassembly

D

dhyams

Regular Contributor
"Yikes, I just got though work

"Yikes, I just got though working to replace my pump impeller, and do a general inspection of the outdrive, and now I'm just thinking that I'm in over my head.

Several things happened that made me really nervous, and I was hoping for you guy's advice on whether or not I should be worried.

1) After installing the impeller (I made sure that the tips of the impeller were curled counterclockwise if you look at it from the top), the driveshaft was VERY hard to turn. Is this normal?

2) There was an unanticipated gap between the sealer that goes on top of the impeller housing. Picture below. I did make sure that the skirt was tucked inside of the impeller housing (that took a little while), and about 3/4 of it is in there. But the impeller is keeping it from sitting flush with the top of the housing.

3) It seems like the right end of the housing is jutting off into nowhere. I know I didn't put it on backwards, but this just seems weird!

4) I dry fit the 2 gaskets underneath the housing...should I have used perfect seal?

5) I can't get the lower and upper housings of the stern drive to mate again to save my life. The copper water tube from the upper housing refuses to slip inside of the black coupler that couples that to the impeller housing.

6) Along the way, genius that I am, I managed to tear off one of the bolt heads that hold the housing on. Luckily after a trip to Lowes to get a screw extractor, and I got it out. Whew. A little frazzled!

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Problem 1"">
131033.jpg
Problem 2
 
"Update on #5 on the list...I

"Update on #5 on the list...I missed the instruction to grease the lower part of the water tube...so surely after I do that, it will slip in."
 
"Do you have the correct impel

"Do you have the correct impelller? Do they match when held side-by-side? If you replaced the housing base, it has an oil seal on the bottom that has to snap into position with a "pop". The slinger seal goes on top of the upper housing over the shaft.

The water tube is to the rear of the LU. Make sure the shift lever is in forward on the LU. Align the water tubes w/the plastic sleeve. Put the square seal on the starboard hole of the bottom half. Both halves should snap together; move the prop left and right a tiny amount to align the shaft spline to the upper housing."
 
"Yes, impeller is correct. As

"Yes, impeller is correct. As far as the oil seal, it is a little round plastic piece that the manual calls the "seal carrier". It was in good condition when I popped it out, so I reinstalled it. The seal in the oil chamber (lower unit) is good...I pressured tested it at 17ps.

Yep, shift lever is in forward, You lost me on the square seal thing though.

Basically I bought this kit and used every part (the first one on the page);

http://mercstuff.com/gen2wp.htm

I have a 1996 Alpha One 4.3L.

Thanks for your help Guy.

And argh, I realize too that I didn't grease the inside of the housing. Once water starts flowing through there, it will be OK right? Or should I disassemble and grease?"
 
"OK, it's now 1 AM, and I&

"OK, it's now 1 AM, and I'm done, whew! I'm feeling a lot better than when I made the first post up there; I was feeling pretty panicked. Now the halves are back together, and pressure tested successfully at 17 psi.

Anyway, here's what I learned....if you see anything suspicious or something that does not match up to your experience, please let me know.

1) greasing the inside of the impeller housing is critical. Much easier to install the impeller, and also the driveshaft would turn OK after the housing was all installed.

2) as far as #3 (the housing jutting into nowhere), I don't see any other way it could be. I looked at it every which way, and compared with the parts I had pulled off.

3) as far as perfect seal, I used it on the paper gasket (the one underneath the wear plate), but not on the one above the wear plate. I hope that was right.

4) Grease that lower part of the copper water tube coming from the upper housing. Critical to getting the halves back together.

So I'm still wondering about the Gap (#2 in the first post, picture above). I found that the procedure that worked best for me during the impeller installation was to install that little sealer first, put the impeller in the housing next, and then slide the entire shabang down the drive shaft and onto the key. Before I tightened down the housing screws, the top sealer was nice and flush. But as I tightened, it steadly popped up and formed that same gap; the impeller was pushing it upwards. Any thoughts on whether this is normal or not?

P.S. As far as shearing off the bolt (in post #1), just a reminder to not be an idiot like I was. I was following my Clymer manual to the letter, and it said to torque the bolts to 60 in-lbs. Cool, so I pull out the torque wrench and go to it. Problem is, the torque wrench of mine is in ft-lbs, not in.lbs. I proceeded to try to torque it down to 60 FT-LBS, a mere 12 times tighter than design. Needless to say, the bolt didn't make it."
 
"Daniel;
First of all; RELAX!

"Daniel;
First of all; RELAX! Trust yourself. You're doing just fine, and it will all work out well. The first time can be a little intimidating, but by the second or third time you will be wondering what all the fuss was about.

It sounds like you have the impeller blades correctly bent. The shaft turns CW from the top, so the blades need to curl CCW from the top. Yes the vertical shaft should be stiff to turn, especially with no grease on the impeller blades.
You don't necessarily need to grease the impeller. That would have been better, and made assembly easier, but is should have a light film of shop lube on it already, and it will work fine once in the water.

Next, you should have a thin gasket between the upper pump body and the flat base plate, correct? Then the lower gasket (with one big D shaped hole) mounts between the pump base plate and the lower gear housing body, correct? If so, it is fine. The lower gasket seals against a flat straight part of the lower gear housing just behind the shaft, and the aft end just floats as you see it.

Did you reuse your flat pump baseplate, and if so, did you mount it the right way up? This is critical because the location of the crescent shaped water intake opening is critical to pump operation. It is likely in correctly as I don't think its possible the get the pumps mounting bolts in if the plate is reversed.

The upper slinger is just snugged down to the pump housing, the way you have it. A little 101 lube here is a good idea.

Reassembling the upper and lower halves can be fun. If the water tube refuses to insert into the coupling (use lots of 101 lube here), you can try first putting the coupling on the water tube, then on assembling the two halves, the coupling is slipped onto the pump outlet nipple. For some reason I have found this seems to work better for me. Make sure you use a new quad seal for the oil passage seal. Once reassembled, you can look through the opening in the front of the upper half with a flashlight and small mirror to make sure the coupling looks like it's where it should be.

Did you remove the entire drive from the boat? I find reassembling the drive leg halves is much easier on the bench with the lower half in a vice, or a stand. This also gives you a chance to inspect your U joints, bellows, and gimbal bearing.

Good luck, let us know how it goes.
Rod"
 
"Daniel;
One further note or

"Daniel;
One further note or two:

The square base plate seal that Guy is mentioning is not used in Gen II's as far as I know.
The rubber hub of the impeller actually sits tightly against the base plate as well as the top of the pump body, and effectively seals both these openings from escaping water. I don't think it will cause any harm where you put it. It does not warrant tearing it apart again to remove it.

The upper so called slinger is there for reasons unknown to me. The fact that it is called a slinger indicates that maybe its purpose is to deflect any debris in the exhaust gases/water stream, to prevent stuff getting into the impeller housing and causing damage I suppose.

Regarding the pump base overhang, there is a tiny water drain hole (maybe 1-2 mm) at the aft end of the base plate that drains the pump, so that the pump does not retain water after engine shut down. This hole must remain open, and the water drains into the exhaust cavity below the pump.

Rod"
 
"Ah! I did notice that little

"Ah! I did notice that little hole and wondered why it was there (since we take soooo much trouble to try to seal the pump!). That explains it.

Re: gasket positioning, in your 2nd post up. Yes, it is as you say.

Re: reusing baseplate...no, I had a new one. But I did mark the old one's positioning and put it in in exactly the same way.

Re: removing drive from boat...yes, it's on a Black n Decker workmate, which is great for holding the thing.

On the bellows, I don't feel like I'm good at inspecting them. I did have some unexplained water in the U-joint bellows (I posted about it a week ago), but I can't find anything wrong with the bellows, and they are nice and pliable. Right now my plan is to look the other way, and midway through next season (maybe earlier) I'll pull the drive and look for water again.

Thanks so much Rod for your input."
 
"Hi Dan,
Get the Factory Ser

"Hi Dan,
Get the Factory Service Manual from Mercury Marine (around $65.00)for your outdrive, and you will see as simple it is to rebuilt the outdrive, not just replacing the water pump. Worth buying the specialty tools when needed. Will make you an expert.
Henry G."
 
"[b]"Get the Factory Servi

""Get the Factory Service Manual from Mercury Marine (around $65.00)for your outdrive,"

Ayuh,......

Even Better than that,......
Clck on this link,+ download it for Free"
 
"Ayuh,.......

[url=""]This

"Ayuh,.......

This 1 seems to be Still working....

Donno if the other 1 is a Temporary Issue,....
Or,...
Maybe Merc. decided to close it to the public......

Nope,..... It won't let you thru to the Manuals,.....

Try this 1,.... It doesn't over quite as many versions, But it's all I've got at the moment...."
 
"Man you must have some inside

"Man you must have some inside info at Mercury, thanks for the links and I hope the other one comes back up."
 
"Nope,.......

I'm just

"Nope,.......

I'm just a Redneck Hillbilly Maineiac sitting up here on the littlest Big Sweetwater Pond(Lake Ontario).........

But,.......
I do have an internet connection to somebody who Does......
I have sent word to Don to see just What's Up....."
 
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