Mercury 9.9 propshaft removal from bearing carrier

[Chadzilla]

I have a 1986 mercury 9.9 serial # 0A927423 model #1010206, and I cannot figure out how to remove the propshaft from the bearing carrier. It appears that the thrust hub should slide off the splines, then the shaft should pull through the bearing carrier, but the thrust hub will not budge. It's obviously splined to the prop shaft. I tried to beat it down, heat it up and beat it down, slide hammer it down and it wont move. There is no pin in it through the shaft, and I can see the splines in front of it and behind it, so it cant screw off. I'm lost. Please help.

 

[Texasmark]

I haven't had a 9.9 for a lot of years and it was a McCullough. I had a new 7.5 Merc in mid '70s time line. The prop shaft was straight. Yours seems to be twisted and looking at the other damages you apparently hit something solid at WOT. Seems to me that if your prop shaft weren't twisted, the parts you want to remove would easily be removed. Looks to me like you would be better off finding a good used lower unit.

 

[Chadzilla]

Seems to me that if your prop shaft weren't twisted, the parts you want to remove would easily be removed. Looks to me like you would be better off finding a good used lower unit.

I found a replacement propshaft and yes it is straight splined. I find it hard to believe that the prop turned a stainless steel shaft like that when it has a rubber bushing inside to prevent damage when hitting stuff. This was a garage sale find so I dont know what happened to it, but I'm willing to bet someone did that trying to remove the bearing carrier by turning it the wrong way. Anyway, thanks for the help.

 

[racerone]

That thrust hub may be splined.----When turned around that becomes the tool to remove the bearing carrier.-----Time to cut the propshaft or thrust washer to get this apart !!!

 

[Faztbullet]

+1 Racer

 

[Texasmark]

" I find it hard to believe that the prop turned a stainless steel shaft like that when it has a rubber bushing inside to prevent damage when hitting stuff."

Me too. When I saw the shaft I couldn't believe my eyes.....on a 10 hp engine no less....a 200 anything's possible, but on 10?????. I'd check for other damage before I put new prop shaft back in the LU.

 

[racerone]

The materials used in many motors is ---" not the same " ---as it was in years gone by.---That includes the small ones.

 

[flyingscott]

It does not surprise me at all that shaft looks like that. The 9.9 Mercury does not have the most robust lower unit, Frail and easy to damage. McCulloch never made a 9.9.

 

[racerone]

I found a Briggs & Stratton lawnmower engine at the local recycle depot.----No money invested.------Took it apart just to see.----Found crankshaft material to be very soft ( bent shaft ) and scrapped this motor.------Found that cams were plastic and gear on camshaft was plastic too.------Things just are not the same today and most folks are OK with the ----" time to buy a new one " ---concept.

 

[Texasmark]

I found a Briggs & Stratton lawnmower engine at the local recycle depot.----No money invested.------Took it apart just to see.----Found crankshaft material to be very soft ( bent shaft ) and scrapped this motor.------Found that cams were plastic and gear on camshaft was plastic too.------Things just are not the same today and most folks are OK with the ----" time to buy a new one " ---concept.

On the time to buy new one concept, I have the same opinion. You have a "device" that is x years old with y operating hours. A repair of one element costs ⅓ the cost of the new unit and considering inconvenience in the tear down process and time involved, waiting on parts once identified and the mess the repair makes, what else is going to need replacing with what broke and all it makes sense to me. This mainly applies to house hold appliances, not marine engines.....I love my 18 year old carbed,115 2 stroker.

 

[racerone]

The concept is quickly coming to marine engines too.-----Factories ( far away ) operate with robots and computers.-----Your local shop with high overhead can not compete with the factory in far away places.

 

[flyingscott]

The OPs lower was built in 86 not recently. It was a junk design from the beginning. It was meant for 6 and 8 hp motors anything bigger and they started getting torn up.