can't remove lower unit!

[Patrick in wa]

1963 evinrude 40 hp, model#40353d. I've removed the 7 bolts that hold the lower unit on, and removed the lower screw on the shift linkage coupler (dropped into the housing, not sure what to do about that). I've rotated the flywheel as I pull on the lower unit incase there is a drive shaft pin. But the lower unit only drops a quarter inch maybe. It is binding on something. Any ideas? Thanks for your help iboats! Love you guys!

 

[boobie]

Re: can't remove lower unit!

The drive shaft splines could be stuck in the crank shaft splines. Try to drive some wooden wedges in the gap and see what happens.

 

[lindy46]

Re: can't remove lower unit!

The drive shaft splines could be stuck in the crank shaft splines. Try to drive some wooden wedges in the gap and see what happens.

X2 - If that doesn't work, try to get some penetrating oil up in there - if someone didn't replace the o-ring at the top of the driveshaft, water may have gotten to the crank and rusted the driveshaft in there.

 

[Patrick in wa]

Re: can't remove lower unit!

Thanks guys! I have a class tonight so I won't be able to try your suggestions till tomorrow but I will keep the forum updated with any progress that I make.

 

[bonz_d]

Re: can't remove lower unit!

With all bolts and shift rod removed it should drop with a few wiggles.

Dropped 1/4" then stopped. I have a very real fear for you as I've just gone through this with a 1988 70hp. In my case there was no way to remove it w/o destroying it. The splines were worn off and the drive shaft spun inside the crank and I was forced to cut the driveshaft.

What you might try is to get the shaft and lower unit back up into position then place a 2X4 and jam the prop so it wont turn and then try to turn the crank to see if the splines will line back up.

 

[Patrick in wa]

Re: can't remove lower unit!

Holy S, that is scary! so your suggestion is to bolt everything back up and somehow prevent the prop from spinning as I start the motor with the electric starter? Would I keep it in forward when I start it? Then try and remove it after each attempt to see if it will drop?

This is complicated by the fact that I dropped the screw for the shift rod coupler into the housing. Will it be safe to try and start the motor or does it fall into the gearcase when this happens? If that's the case I have a catch 22 on my hands.

Thanks everybody for taking the time, and sorry for all the questions. I've never taking a motor apart before.

 

[bonz_d]

Re: can't remove lower unit!

No, what you want to try and do is to get the driveshaft back up into the crankshaft. Do not bolt it back together and do not try and start it! Turn the flywheel by hand. The idea is to keep the driveshaft from moving while trying to turn the crank. Also you will want to try this in a counter-rotation direction.

If this the case and the driveshaft has spun then in all practicality it's done because there most likely isn't enough spline left on either the driveshaft or the crank to make it salvageable.

I really hope I am wrong and this isn't your case. In this thread you will be able to see a couple pictures of the driveshaft that came out of that 70hp Evinrude.

http://forums.iboats.com/johnson-evinrude-outboards/1988-evinrude-70hp-drive-shaft-stuck-603622.html

 

[Patrick in wa]

Re: can't remove lower unit!

Ok, thanks bonz_d. I couldn't picture what you were suggesting. That makes more sense now.

 

[gozierdt]

Re: can't remove lower unit!

I agree with boobie and lindy46. You need to try a little more force to pull the driveshaft out of the splines in the crankshaft. The wooden wedges are a good idea. I've pulled several salt water motors apart that had some corrosion up in the spines and needed some persuasion to come loose. We're not talking about a 20 ton press here- the wooden wedges are a good idea. It's hard to be sure penetrating oil is getting up to the right place- I think about turning the motor upside down, and spraying the oil on the visible part of the driveshaft- it should run down the driveshaft and into the splined area (unless the shaft still has the o-ring just below the splines in place...but it's worth a try).

 

[Patrick in wa]

Re: can't remove lower unit!

Finally had a chance to work on the motor this morning and thanks to everybody's input I got the lower unit off! The wooden wedges did the trick. The splines look great on the drive shaft probably just had some corrosion in there because I do use it in salt water, should of known it just needed some persuasion. Thanks again for everybody's input, iboats sure is a great resource.

 

[bonz_d]

Re: can't remove lower unit!

Patrich I'm very glad to hear it. Hopefully the rest goes much smoother for you!

 

[lindy46]

Re: can't remove lower unit!

Don't forget to install the o-ring at the top of the driveshaft to prevent this problem in the future.