Mercury Drive shaft is stuck in the motor head!!!

[sonoma_dog]

I am stuck! I just bought a 1985 35hp mercury outboard, Serial number: 6629125. I tried to replace the water pump and am not able to drop the lower unit. I have removed all five nuts as shown in the pictures!


After all the research on the internet, I am suspecting the drive shaft is stuck at the motor head. So I have mounted the outboard upside down, drilled a 1?1/2 inch hold and spray a LOT of liquid wrench penetrating oil in where I think the drive shaft is stuck (See pic) . After 4 days of penetrating oil / hitting it with hammer/ shaking it and the drive shaft still seems like it?s stuck there.

My first question is?. Is it really the drive shaft that causing problem? And if it is?..

WHAT SHOULD I DO NEXT?

1) Continual applying more oil / shaking it more

OR

2) Apply heat with a torch on the drive shaft. I am afraid that the shaft gets so hot cauing the plastic housing on the lower unit melt.


OR

3) Cut the drive shaft??and what to do afterward? how to remove the shaft from the motor head? And Can I weld it back together.

OR

4) Just grab a beer and say **** it?????.

Any advice will help! I really want to get this outboard working!

Thanks in advance!!!!

 

[bgc]

Re: Mercury Drive shaft is stuck in the motor head!!!

KRIOL...you can find it online...
Its what I use on my old Mercs and we rely on it heavily it the shop. It takes a couple day to work but it get the job done.....

Penetrating-Lubricating Oils

 

[erie_guy]

Re: Mercury Drive shaft is stuck in the motor head!!!

From the gap you pictured, it appears you have already gotten it to drop about 0.5". I would lubricate it well with kroil and then use the nuts to retighten the lower unit - drawing the lower unit and power head together. Repeat this several times, then use wedges to pry the two housings apart.

Was this used in saltwater ?

erie_guy
Port Clinton, OH

 

[sonoma_dog]

Re: Mercury Drive shaft is stuck in the motor head!!!

KRIOL...you can find it online...
Its what I use on my old Mercs and we rely on it heavily it the shop. It takes a couple day to work but it get the job done.....

Penetrating-Lubricating Oils

oh wow, these stuff are a lot more expensive then liquid wrench. I will use liquid wrench for couple more days. if it still doesnt drop, i will get Kriol. I bought 4 cans of liquid wrench from amazon and i don't think i will ever use it after this project haha.

 

[sonoma_dog]

Re: Mercury Drive shaft is stuck in the motor head!!!

From the gap you pictured, it appears you have already gotten it to drop about 0.5". I would lubricate it well with kroil and then use the nuts to retighten the lower unit - drawing the lower unit and power head together. Repeat this several times, then use wedges to pry the two housings apart.

Was this used in saltwater ?



erie_guy
Port Clinton, OH

I believe so it was used in salt water, and it had been sitting out door for couple of years. so i think the shaft is stuck pretty good there.

I am assuming the only place i need to lubricate is the end of the shaft just like the picture shown, right? I dont need to lubricate the water pip next to it?

Thanks !

 

[jslu]

Re: Mercury Drive shaft is stuck in the motor head!!!

I believe so it was used in salt water, and it had been sitting out door for couple of years. so i think the shaft is stuck pretty good there.

I am assuming the only place i need to lubricate is the end of the shaft just like the picture shown, right? I dont need to lubricate the water pip next to it?

Thanks !

sonoma dog,

I had a similar experience with a 1989 35 HP Merc that I rescued for 60 bucks as a barn find parts motor, salt water used.
The lower unit was stuck fast and what worked for me was to install opossing metal wedges between the lower unit and the housing in the area of the drive shaft taking care not to impinge on other parts. Each day for a week I drove the wedges in a litlle deeper with a few blows from a hammer and after a week of this, it finally broke free. Hardwood wooden wedges did not work because they distort (shave) and do not apply the constant force required to break this bond. I did not hang the motor upside down and drill access hole to prvide a port for liquid penetrants at the rust crank/driveshaft interface.

The copper water tube fits into a rubber grommet, not your problem.

Have you looked at the shift shaft connection to lower unit? This is a splined coupling also prone to rusting hard enough to give you similar problems. I doubt the driveshaft can be welded successfully.

Final disposition of my 1989 Merc 35: The engine had power tilt which originally attracted me to it. Then I proceeded with a "let's see what works" approach and after replacing the water pump it was a series of successes and I have been using this engine for three years now and it idles smooth and strong at 600 RPM in gear and runs like a dream at 6000 RPM.

Hang in there!

John