removing lower unit

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
i remove 4 screws/bolt and its not coming apart. did i miss a screw or do i need to pry it loose?
 
Joined
Sep 5, 2007
Messages
1,790
Re: removing lower unit

make sure there isnt one more bolt(allen head) recessed up in the end above the prop. If not I would use a putty knife to break the seal and a rubber mallet to tap it loose.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

i found one more bolt, 5th one. after i pry it and got a 1/4 inch gap all the way around i shim it with some wood. it look like it doesn't want to open anymore. is there something still connected?
 

mariner45hp

Seaman
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Jun 6, 2007
Messages
58
Re: removing lower unit

by thw way the engine is an 87 45hp mariner. got the 5 obvious bolts still not coming apart.
 

AMD Rules

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Sep 23, 2004
Messages
1,707
Re: removing lower unit

Assuming you have removed the 4 necessary locknuts, including the one hidden beneath the trim tab? The only other thing that could be attached is the rubber speedometer tube. It would be unusual for it to be that tight, but possible. The speedometer tubing exits out the front of the gearcase upwards and the out the front of the lower driveshaft housing bracket. If it is there, you should see a union joint where it can be disconnected.

Is this a saltwater motor? Not uncommon for the drive shaft and/or shift shaft splines to corrode and sieze up and making removal difficult or in some cases near impossible. Be exta careful when trying to pursuade it to come loose, as the antiventillation plates are known to crack/fracture if they are hit or pryed upon.

Good luck
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

i am going to keep shimming it slowly, hopefully it will come apart. w'll keep u posted.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

no luck!!!!! is the rod or the gear shift rod still connected some where? any other ideas????PLEASE HELP!!!!!!!!!!!!!!!!!!
 

Paul DuLaney

Petty Officer 2nd Class
Joined
Mar 17, 2007
Messages
145
Re: removing lower unit

I had problem with a 85hp ,it was the fount bolt had corroded to the housing.After tying it together with bunji cords and soaking it with blaster penetrating oil in came apart the next morning after putting a LITTLE pressure with a large bladed screw driver and tapping lightly with a rubber mallet.Be careful when it comes loose it's coming out and down now!
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

i soaked it with wd40 last night. hopefully it loosen it up a little. will give it another whack today
 

*EdC*

Senior Chief Petty Officer
Joined
Oct 31, 2007
Messages
661
Re: removing lower unit

Get yourself some PB Blaster! Home Depot sells it! WD-40 won't help you with this. Also, don't whack it! you can easily crack the aluminium. Keep using small wood wedges tapping them in evenly all the way around. The unit must come down evenly, If it is slightly cocked it wont come.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

thanks for the info and heads up on not whacking it. i was getting to the point where i was going to give it all i can whacking it apart. :mad::mad::mad:
 

bass_assasin

Cadet
Joined
Apr 10, 2008
Messages
21
Re: removing lower unit

I do not have the knowledge that some of the guys in here do, but I do know som of the older motors do have a cotter pin in the shifting mechanism....the 85 Johnson 40hp that I had years ago did.dbl check the rod up thru the foot where it connects (where your speedo line comes out)and under the cowling.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

this one is a stubborn one ,it won't come apart:mad::mad:. now i have about 1/2inch gap all around and won't come apart. it fills like some thing is still connected somewhere. please help!!!!!!!:confused::confused:
 

AMD Rules

Lieutenant Commander
Joined
Sep 23, 2004
Messages
1,707
Re: removing lower unit

Is this a saltwater motor? Not uncommon for the drive shaft and/or shift shaft splines to corrode and sieze up and making removal difficult or in some cases near impossible. Be exta careful when trying to pursuade it to come loose, as the antiventillation plates are known to crack/fracture if they are hit or pryed upon.

Sounds like your drive shaft and/or shift shaft are corroded STUCK. They are splined connections, and under normal circumstances should slide apart with ease. One thing some people have tried is to invert the motor, then let penetrating oil run down the drive shaft and shift shaft to soak the splines. I'm not sure with only 1/2" gap that you are going to be able to reach the driveshaft to oil it.

Might be worth considering taking it to a shop to have them look at it. They might have other ideas.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

with the 1/2 inch gap i got, i don't see any signs of corrision on the shift shaft splines. it s as shiny as it can be. AS for the drive shaft, if i can start the engine its not corroded right? i start the engeine before i started working on it.
 

AMD Rules

Lieutenant Commander
Joined
Sep 23, 2004
Messages
1,707
Re: removing lower unit

The motor will run just fine with corroded drive shaft splines (just wont let you take it apart). The crankshaft has an internal spline, the driveshaft external. They basically become one. It is often quite moist up there, and promotes corrosion.

I can't be certain, but that the symptoms you are experiencing.

Good luck.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

i was told to get some pb blsater from home depot to help free up any corrision. i don't what pb blaster is, what is it?
 

AMD Rules

Lieutenant Commander
Joined
Sep 23, 2004
Messages
1,707
Re: removing lower unit

It might be helpful to see a picture of the 1/2" gap you have achieved, to confirm that it looks like you have all the fasteners removed. Can you post a pic?

PB Blaster is a penetrating liquid.
 

mariner45hp

Seaman
Joined
Jun 6, 2007
Messages
58
Re: removing lower unit

right after i posted the last one about pb blaster, i asked why did i do, i coulda gone on line check it my self. which i did. thanks for responding to it anyways. anyhow i was gooleing on how to remove lower unit for 45hp mariner and this came up. I'm trying to replace impeller (89 mariner 45hp) and my question is do i have to remove shift pin before lower unit will drop?
So far I remove 5 bolts total but seem like something ios holding back. Shift linkage towards engine has a pin going into this mechanism and i was wonder if that has to come out before lower unit will drop..
: some else responsed yes to this question. does this apply to my 87 mariner also? if so where? i looked all over but can't locate this pin. need some pics or skeck. i will take some pics of the gap on my engine and post it 2morrow, its dark outside already..
 
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