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23 L OMC Cobra Upper Gear Housing Removal

J

jbutman

Member
"I have an '89 OMC Cobra a

"I have an '89 OMC Cobra and the shaft that goes back to the impeller pump broke near the impeller (I wrote about it in a different post). Anyways, I got the yolk assembly today and called around to the boat repair places here and no one would touch it. So I went on to Seloc Online where I purchased a manual last year. It is only about half helpful, so I looked on Crowley Marine and found that more helpful. My question is can I remove the lower unit without removing the shaft into the motor (disconnect shafts at U-Joint)? I don't want to buy an alignment tool. Also, what is the easiest way to drain the oil in the lower unit, and then replace it? How much oil does it hold, and what type should be used? I have also found some different parts diagrams online, but didn't remember to book mark them, so I would like to see a good diagram of all the upper gear housing parts with the part names if anyone knows of any place to find them. Does anyone have any other suggestions to make the shaft replacement easier since I'll end up doing it myself? Thanks."
 
"The BRP (OMC) part pa

"The BRP (OMC) part page is here:
http://epc.brp.com/login.aspx?ReturnUrl=%2fdefault.aspx%3fbrands%3dej%26lang%3dE&brands=ej&lang=E&AspxAutoDetectCookieSupport=1
The impeller shaft is a separate part (#36) and may, if You know the trick, be changed without removing the drive. However If You want to change the whole input shaft, that is a different story!
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"I would like to just replace

"I would like to just replace the impeller shaft... but couldn't find where I could buy that separately. Would you mind sharing the little "trick" to just replace the shaft? Also, I couldn't get to the BRP link you posted. Thanks."
 
"First You have to note that t

"First You have to note that the shaft has to be installed to a certain depth. 'Normally' a special tool is used, but You may manage without if careful. If shaft is broken, drill a center hole and install a screw, the knock it out with a slide hammer and install the new shaft. Remember to remove cover #45 and replace seal #47."
 
"How do I take the new shaft o

"How do I take the new shaft out of the new yolk assembly? As I said, I wasn't able to find just the impeller shaft, only the whole assembly. Also, do you know what part # seal #47 is? Thanks."
 
"You don't! If You remove

"You don't! If You remove it, it will loose its press-fit.
Follow the link above and You will find all part numbers once You have navigated through to Your engine. View catalog - stern drives - 1989 -2,3 -upper housing. The shaft is a dealer item."
 
"I'm still confused on how

"I'm still confused on how to remove just the impeller shaft (#38) then. I had to order the whole yolk (stub and water pump shaft #37). I want to replace just the impeller shaft so I don't need to drop the whole lower unit. If I drill out the broken impeller shaft (#38) and pull it out, then I should be able to pull the impeller shaft (#38) out of the new stub and water pump shaft (#37) and install the impeller shaft (#38) into the existing stub, correct? Should I return the stub and water pump shaft (#37) and contact a dealer for just the impeller shaft (#38)? There aren't any dealers around here so I would need to find one. I am just really trying to avoid dropping the whole lower unit since it was only the impeller shaft (#38) that is broken near where it fits into the impeller. If I will loose the compression fit though, is this really a viable solution? Thanks."
 
"The problem with the impeller

"The problem with the impeller shaft is that it is just a round shaft, no splines or keys. Once installed, it may not be pulled out and reinstalled, either in the old shaft or a new one. The fitting will just be too loose!
You have two options:
1: Get a new impeller shaft only.
2: Bite the bullet, pull off the drive, dismantle upper drive and change the complete shaft.
What is Your location?"
 
"I am located near Bismarck, N

"I am located near Bismarck, ND. So if I get just the impeller shaft and install it, then there won't be a problem with it being too loose in the existing stub that is in there? I'm just trying to understand why it would matter if I pulled the shaft out of the stub I bought, and install it in the existing stub. It's the same concept as buying just the impeller shaft and installing it, unless the impeller shaft alone is different from a shaft that comes in the stub already, but that doesn't make much sense. Just a common guy trying to understand the technicallity of it..."
 
"A shaft with press-fit alread

"A shaft with press-fit already installed once, will be slightly 'compressed'. Pull it out and measure with a micro meter, a used shaft will have less dia than a new one.
Secondly You may not manage to get it out without destroying it. The shaft is 'soft' and You would nee to put it in a vice. When pulling it out, it will most likely get quite some score marks."
 
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