'72 65HP Evinrude-- replacing seals/impeller in lower unit

[mike64]

At the end of last season I found water in the LU oil when I replaced it. So I just picked up replacement seals and a new impeller. Now I've reviewed the procedure on dropping the LU in the OEM service manual and in some posts here, and I reviewed some good advice on pressure testing in one of my posts from last year:
http://forums.iboats.com/showthread.php?t=273386

I'm kind of leery about removing the LU so I wanted to ask you guys with similar motors what advice/stuff to watch out for from their own experiences.

What I understand so far: It looks like after I drain the LU oil, I disconnect the shift cable from the powerhead, and remove several bolts that hold the LU on. Then I remove the LU being careful with the shift cable and a plastic guide tube that's in there.

It looks from the manual that the impeller is easy to get to, and I have an o-ring that I believe goes on top of the LU where it meets the midsection of the motor. That looks easy too. But I have 2 metal-backed rubber seals that apparently go on the prop shaft and drive shaft. Are those hard to get to? How much am I going to have to take apart?

Will I need any special tools?

Any tips on making the job easier? I read where a guy tied fishing line on his shift cable to fish it back up through the works when he put the LU back on.

 

[Defiant]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Get a service manual for your motor it explains it better then we can look on Ebay or here at Iboats

 

[mike64]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Get a service manual for your motor it explains it better then we can look on Ebay or here at Iboats

Thanks, but as I said I have the OEM service manual. I'm looking more for advice from people who've dropped their LUs in similar motors and have first hand experience. The service manual assumes you have a lot of experience already and all the proper tools.

 

[spencroy]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Hey Mike,
I am by no means an expert, and I probably shouldnt even reply to this post, but I know the first time I dropped my lower unit on my 1977 Johnson I was a bit apprenhensive. I can say though (now that I have dropped it about 10 times .. due to me being an idiot for the most part) that all in all its not to bad. I think the first post I ever put out here one of the experts suggested I replace the impeller as soon as was possible. I put this off for nearly a year, but due to having a dog-eared clutch dog and reverse gear I had to tear into the LU.

First off the advice on the manual is very sound. Without it I would have been lost. I only could get the SELOC manual at the time, but for the LU it seemed to serve pretty good.

As for lowering it, basically you disconnect the shift rod at the Upper, then you are looking at removing the 4 main bolts, and the 2 under the trim tab (think that is what its called, one of those is sorta hidden so get the book)

Once you have the unit loosened its just a matter of dropping it straight down (personally I tilt my motor a bit to make it easier to pull out)

To give you a very rough idea of what you will see when you get it dropped out of there:


They key point is do not be intimidated (if I can do it anyone can, because I am a horrible at mechanical things). Just keep the drive shaft and shift rod from bending and you should be fine. Good luck
Roy

 

[mike64]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Thanks spencroy! That's exactly the type of first-hand advice I'm looking for.

How about changing the prop shaft and drive shaft seals-- can anybody tell me how difficult that is?

 

[spencroy]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Prop shaft is easy, its getting to it that is a nightmare. As you remove the prop after that is when things get interesting. I dont recall what they call that big spacer device, but if its stuck you are going to have hell getting it out.

After that the next HUGE obstical is the snap rings. If you do not have a good set of snap ring pliers (that open to at least 2.5") I wouldnt' even start into that part of the lower unit. That one little tool nearly ended my boating for life (as luck would have it I found a decent pair last night at Harbor Freight for 12 bucks, but this is the first time they have carried them, they never had em when I needed em):

http://forums.iboats.com/showthread.php?t=272197 (I must have done a crappy job on that one cause no one responded
but got some help on this one:
http://forums.iboats.com/showthread.php?t=272209

After that its pretty easy. If you have not done so make sure to study the diagram of the lower unit in the BRP catalog (that helped me quite a bit).
http://epc.brp.com/login.aspx?Retur...rands=ej&lang=e&AspxAutoDetectCookieSupport=1
Other than the snap rings everything else is pretty easy in my opinion and I am not certain the seal you are talking about may be on the outside of those snap rings so it will be even that much easier.

As for the seals on the waterpump those are easy to get to, but one word of advice. After you remove the bolts for the waterpump and start to slide the unit up the driveshaft there is a little key (I forget the name) that falls out at about the base of the driveshaft. Make sure you keep an eye out for it as your going to need it again.

Also may be a good idea to replace the gasket between the upper and lower in the exhaust chamber while your in there. I personally (due to the fact that my junky boats are always being worked one) would drop the lower, get my parts list together, order, and then rebuild. (for instance things like the o-rings on the lower unit lube ports I did not order and had to wait for after I finally got through with my water pump. No sense spending a 100 bucks on parts only to have everything fall apart due to a .25 cent o-ring.

 

[mike64]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Thanks again Roy!

 

[ray starcraft]

Re: '73 65HP Evinrude-- can any one tell me how to drop lower unit

Re: '73 65HP Evinrude-- can any one tell me how to drop lower unit

I need to drop lower unit to install impeller kit....something I have never done.
I have removed the four bolts under the cavitation plate and one under I think where the zink goes.
Still seems held together
Thanks in advance

 

[F_R]

Re: '73 65HP Evinrude-- can any one tell me how to drop lower unit

Re: '73 65HP Evinrude-- can any one tell me how to drop lower unit

I need to drop lower unit to install impeller kit....something I have never done.
I have removed the four bolts under the cavitation plate and one under I think where the zink goes.
Still seems held together
Thanks in advance

There are 7 bolts to remove. The four that you mention, the one holding the trim tab on, the one that you will see once you get the trim tab off, and one forward of the trim tab. Also, the shift wire or rod, as applicable.

 

[ray starcraft]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Thanks for the reply,
I can account for 6 bolts...not sure where the seventh is?

 

[LiLGrady17]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

my 85 has the four around the front, one holding the trim tab, one in the trim tab cavity, and if you look up from the under the skeg/prop, there is a hole indent & the last bolt is in there, for 7. Not sure if yours is the same, but most of these engines are very similar..

 

[ray starcraft]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

Well I found the seven and it still does not seem to want to come down.

 

[kyleg001]

Re: '72 65HP Evinrude-- replacing seals/impeller in lower unit

did you ever figure this out?