1988 6hp impeller seal question

crossbowjim

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Hi, I am getting ready to replace the impeller on my 88 6hp evinrude for the first time.

Are there any pitfalls or problems I should be aware of? While I have it apart I planned on replacing the seals at the prop, however, in looking at the parts diagram there are several seals and o rings associated with the prop. Which of these should I replace? As to the remainder of the lower unit, while I have it apart which seals orings should I replace. I plan to purchase the entire impeller kit, so of course all those seals will be replaced, but are there any associated seals that are not included that should be replaced?

And lastly, I dont think the impeller has ever been changed. Any ideas on how to lossen the bolts? I haven't tried them yet, but is there anything I can do ahead of trying them that may save me some time or problems later. Thanks for all of your help.
 

jasper60103

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Re: 1988 6hp impeller seal question

I wouldn't reseal the gearcase unless it had water intrusion, i.e. oil is milky in color. Just drain the gear oil and refill with 80-90W outboard gear oil, and install new vent/fill washers.

Yes, I would change the impeller or replace the entire waterpump if needed. The waterpump kit will include the gaskets. Be sure to get yourself an OEM service manual. -jasper
 

crossbowjim

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Re: 1988 6hp impeller seal question

Thanks for the response. Apparently I am getting water in the lower unit as the oil is milky white. I found that out when I noticed the oil was dripping out of the water intake. Which I am going to assume is coming from the lower unit and as I believe the impeller and oil should not be meeting this would indicate a bad seal. Am I correct in my assumption? Or could the water be getting in somewhere else and just coming out of the intake?
 

Vic.S

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Re: 1988 6hp impeller seal question

To identify the leaking seal its necessary to do a pressure and vacuum test but unless you have the facility to do it the easiest thing is to replace all the seals (and the pump impeller while you are in there)

LOWER UNIT DIAGRAM HERE

If you really have gear oil leaking from the water intake then the drive shaft seals are the ones that have failed (#27 in the diagram) Most likely to have failed because they get damaged by fishing line etc are the prop shaft seals (#2 and #3) (Note the seals are double and are fitted back to back on both shafts)

Might as well replace the shift rod O ring as well but not likely to be the problem (#26)

Also repace any gaskets and O rings you disturb while doing the above.


BUT BUT BUT a common cause of water ingress is failing to renew the washers (#31) on the drain and level plugs. Dont reuse them.
You might also like to read the item on "Oil leaking around the lower unit" on the Engine FAQs board SEE HERE
 

wilde1j

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Re: 1988 6hp impeller seal question

Could be drive shaft seal or if, your motor has gear shift, could be shift rod seal as well. Or it could be the drain/fill screw washers, your choice. If you suspect seal leakage, pressure and vacuum testing is how you find the leaker(s).

If you find the leaker, make sure to install the new seal slightly offset from the old one if there is any evidence of shaft grooving.
 

Vic.S

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Re: 1988 6hp impeller seal question

By the Way

If its a longshaft model take the extension off with the gear case, then remove it after cleaning up the drive shaft.
 

crossbowjim

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Re: 1988 6hp impeller seal question

Wow thanks for all the input. I knew this site was a gem when I found it! Based on what was written I am willing to bet it is the drain and level plugs. Two years running I used the same seals! Now that I know better that won't happen again. But as the impeller has never been changed I guess I will have it done.

Speaking of having it done. I got an estimate of $180.00 labor plus parts. That is for changing the impeller and the seals around the prop. Based on everyones experience is this a self do job or do I bite the bullet and pay someone. I am estimating the total cost around $250.00 all said and done. What do you guys think?
 

wilde1j

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Re: 1988 6hp impeller seal question

If you're thinking of doing it yourself, get an OEM shop manual first, then decide.

You can get an OEM manual from outboardbooks.com, Ebay, or elsewhere. Don't waste your time and money with the third party books like Clymer or Seloc.

BTW, if you do the water pump, don't just do the impeller, do the whole pump, since the existing one is likely 11 years old with a lot of hours.
 

Vic.S

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Re: 1988 6hp impeller seal question

I have a 6hp (1984 so practically the same)

Jobs a doddle. I don't have a manual!

Made the mistake once of pulling the LU off without the extension and the impeller pin damaged the pump housing because the shaft did not slide though the bush in the extension

I also have to confess that I have never changed the seals on the drain and level plugs despite all the advice to do so.

Also never replaced the pump housing (even straightened it and reused it after the above incident. (dont know why wilde1 thinks the pump housing is likely to be 11 years old ... could be 21 years old!)

Bolts may be problem if its a long time since last dismantled. Heat may help. Sharp taps on spanner with a hammer perhaps less likely to wring the heads off than steady force (gentle taps with big hammer usually better than wanging away with a little one)
 

crossbowjim

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Re: 1988 6hp impeller seal question

Wild1, am I correct in assuming that by water pump you mean the entire impeller assembly not just the impeller itself?
 

wilde1j

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Re: 1988 6hp impeller seal question

Correct. The pump body and wear plate are probably worn/scored and the complete kit gets you all the gaskets and other soft parts as well. If you're going to take the time to pull it all apart, you might as well replace all. Not that much $.
 
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