1974 115hp Upper shift shaft rusted through

[pdehardon]

On my 1974 Merc in line 6 the upper shift shaft is exposed just above the lower unit. It is there that the shaft rusted through and I am stuck in FWD. I removed the lower unit and the female end of the upper shift shaft came off with the lower unit. I have the Mercury shop manual for years 72-89 but cant find any info on the upper shift shaft. The top end of the shaft appears to be held in by a roll pin. I do have an old 1980 Merc 40hp with a bad power head. I had it mostly disassembled and was able to tap out the pin and drop the shift shaft out of the motor and it fits the splined end of the lower shift shaft sticking out of the lower unit of my 115hp.

2 Questions:

Does anyone think that the shift shaft from my 40hp will work on the 115? I dont know if the part numbers are the same as I cant find a number for either. The ends that I can see look the same but I cant measure the length of the shaft for the 115 as I have not been able to extract it yet.

2nd. Can anyone offer advise on removing the upper shift shaft? I was barely able to tap out the pin holding in the shaft on the 40hp even with everything but the power head removed. Of course I want to disassemble as little as possible on the 115 to get the old shaft out and the new one in.

Any tricks/advise will be appreciated.

 

[merc850]

Re: 1974 115hp Upper shift shaft rusted through

The best way to remove the shaft is by lifting the power head off the DS housing, this is how they do it, good time to check for carbon buildup in the exhaust tower . Get a gasket from a Merc dealer and you're good - he might have the shaft too! I painted mine to stop corrosion.

 

[carholme]

Re: 1974 115hp Upper shift shaft rusted through

pdehardon;

Do you have your engine s/n? Are you sure that is the female end of the upper shift shaft or could it be a coupler?

Here is a link to the '74 115 upper shift rod and you will see that below certain serial numbers they use a coupler between the upper and lower shift shafts. See coupler, item 19 in the link.

http://www.crowleymarine.com/mercury-outboard/parts/463_17.cfm

Gerry

 

[pdehardon]

Re: 1974 115hp Upper shift shaft rusted through

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[pdehardon]

Re: 1974 115hp Upper shift shaft rusted through

Follow up:
I was able to remove and replace the shift haft without removing the power head. The top of the shaft is splined and attached to the lever at the top by a roll pin. I was able to tap out the pin and drop the old shaft out the bottom after removing the foot.

Back on the water now.
Thanks guys.