lower unit help

I

inboardnewbie

Seaman
Joined
May 16, 2011
Messages
65
Hey guys i just bought a mercury thunderbolt 800 80 hp serial # 3054534 and im having a couple issues.
First is i cant find out what year it is and 2nd
I cant figure out how to remove the lower unit.. its not spitting out water thru the pee hole. Ive removed all of the bolts and nuts and i have pryed it about 1/4 inch and it wont go no further... am i doing something wrong?
Any and all help will be greatly appreciated
 
C

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: lower unit help

That s/n comes up as:

80 1971 E S&L 2986444 - 3186282 2991034

From here:

MERCURY OUTBOARD MODEL YEAR GUIDE 60 HP - 100 HP -- Mastertech Marine

Parts Listing for model 1800101:

MERC 800E - Mercury, Mercruiser, Force, etc. Parts Lookup

I don't know whether you have a manual or not but here is a link to the condensed version of the Clymer manual. Download it soonest to your computer as the link is short lived. It will help you determine that everything is disconnected.

Small Engine Repair Reference Center Home: MERCURY - MERCURY FOUR-CYLINDER MODELS (1969-1989).

See figure M12-60 on page 286.

If you are sure it is all disconnected, you probably have corrosion holding the driveshaft splines where they are splined into the bottom of the crankshaft. It can take a lot of work using wedges to try and get it to dislodge. Try it with wedges and see how it goes.

Believe me it is very common and this forum has many stories of people in the same position, some who have resorted to trying to start the engine to see if it will break free.

Gerry
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,100
Re: lower unit help

need to remove 5 nuts and a hidden bolt. Did you get 'em all?
 
I

inboardnewbie

Seaman
Joined
May 16, 2011
Messages
65
Re: lower unit help

Yup i removed 5 nuts and hidden bolt i pryed it down 1/4 inch and thats as far as itll go it acts like something else is holding it.. it doesnt have to be in gear or anything does it?
 
I

inboardnewbie

Seaman
Joined
May 16, 2011
Messages
65
Re: lower unit help

Ok i got it off.. just a few wedges and it popped off, now on my gear case the shaft moves about 1/2 inch in and out and if i push it in tight it will turn the driveshaft but if i pull it out i can spin it either way freely. What would be the cause of that
 
C

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: lower unit help

Does your driveshaft have the pin and spring, items 10/11 in this link?

Mercury, Mercruiser, Force, etc. - GEAR HOUSING ASSEMBLY, COMPLETE - MERC 800E

Your s/n indicates that it shouldn't be there but if a later gearbox has been installed, this would mean that it has the tapered bearing, item 15 and spiral cut gears. In this case, when pulling up on the driveshaft, it will react in the way you have described.

Gerry
 
I

inboardnewbie

Seaman
Joined
May 16, 2011
Messages
65
Re: lower unit help

No im talking about my prop shaft moves that much i have another outboard on my boat now and i cant move the prop shaft in and out at all. Im wondering if the housing just wasnt in there far enough?
 
C

carholme

Rear Admiral
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Messages
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C

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: lower unit help

Item 15 is pictured at the top of the driveshaft but is rather a moot point now as it is the prop shaft, not driveshaft we are discussing.

Have you tried the bearing carrier nut yet to see if it is tight or not?
Gerry
 
I

inboardnewbie

Seaman
Joined
May 16, 2011
Messages
65
Re: lower unit help

Thanks so much for your help. As for that nut i did notice when i pulled the carrier out, that that nut didnt seem very tight to me so maybe thats all the issue is. I hope anyway. Im out of town right now so i cant double check, what else could cause it incase thats not the problem.
 
Yesterday

Yesterday

Petty Officer 1st Class
Joined
Feb 21, 2012
Messages
354
Re: lower unit help

inboardnewbie said:
Thanks so much for your help. As for that nut i did notice when i pulled the carrier out, that that nut didnt seem very tight to me so maybe thats all the issue is. I hope anyway. Im out of town right now so i cant double check, what else could cause it incase thats not the problem.
Click to expand...

Torque specs put the spanner nut at around 200 ft pounds. If it was loose and there is a lot of play it would make me wonder if someone's been inside of it recently.
 
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