9.9HP Seized Driveshaft

[scout-j-m]

The driveshaft on my 1982 9.9 hp Evinrude is sized in the crankshaft splines. I was able to remove the LU by pulling the driveshaft out of it and through the water pump housing. I have it upside down right now soaking with PB Blaster which is all I had on hand. What would the best penetrating oil be for this situation? And any tips for pulling it after it has soaked? I tried after a few days of the PB Blaster to use a pair of small vice grips, tapping on them with a hammer but it didn't budge.

For what it's worth, I'm converting from long shaft to short, so a damaged driveshaft wouldn't be that big of a deal to me. So if all else fails and there is a good method of removal where it may be damaged beyond repair I am open to it.

 

[hardwater fisherman]

I have not had to try it yet but others here said acetone mixed 50/50 with transmission fluid works well.

 

[scout-j-m]

I have not had to try it yet but others here said acetone mixed 50/50 with transmission fluid works well.

Thanks. I had read ATF works but hadn't seen anything on mixing with acetone.

 

[the machinist]

You will need to fill at LEAST a pint of oil down the housing if the motor is turned upside down as there is a internal tube over 3" long that it would have to fill over to do any good at the spline.

I have used a Vise Grip clamped tightly on the shaft in an an area can be damaged but not near a seal. Clamp ity down TIGHTLY & then using a medium hammer pound on the Vise Grip. After it comes out you can file the gouges out.

 

[lindy46]

Damaging the driveshaft is not the problem, it's damage to the crank that is the real problem, as that is what will be rusted. Someone most likely left the O-ring off the top of the driveshaft allowing water to get in the crank.

 

[scout-j-m]

You will need to fill at LEAST a pint of oil down the housing if the motor is turned upside down as there is a internal tube over 3" long that it would have to fill over to do any good at the spline.

I have used a Vise Grip clamped tightly on the shaft in an an area can be damaged but not near a seal. Clamp ity down TIGHTLY & then using a medium hammer pound on the Vise Grip. After it comes out you can file the gouges out.

Ok, I didn't realize it would take that much. My PB Blaster may not have even reached anything down there. I had sprayed it directly on the end of the driveshaft and allowed it to run down it on its own. Even then though, I was still seeing lots run out between the leg and the lower cowling.

 

[scout-j-m]

Damaging the driveshaft is not the problem, it's damage to the crank that is the real problem, as that is what will be rusted. Someone most likely left the O-ring off the top of the driveshaft allowing water to get in the crank.

That would suck but it wouldn't surprise me. I'm capable of pulling the powerhead or even having to replace the crank if it comes to that but that is a serious headache for a motor that runs excellent in the barrel. Maybe a good soaking will eventually break it free somewhat cleanly. Fingers crossed.

 

[scout-j-m]

Update:

I never used anything other than PB Blaster and hadn't sprayed any of it on in a while either but I was still able to break the driveshaft free last night. I used a new heavier duty pair of vice grips and a decent sized hammer. It made some pretty long and deep gouges of the driveshaft but they filed down to the point of no sharp edges. I locked the vice on the shaft between the marking where the LU seal sits on it and the LU splines.

After cleaning the driveshaft up with a wire wheel, the upper portion housed in the exhaust leg had some pitting, however, the splines that mate with the crank cleaned up nicely.

Any tips on cleaning the crankshaft splines? I have a gun cleaning kit which may work plus the motor is still upside down and soaking in penetrant so it may loosen up some more. I'm turning this motor into a short shaft and at some point am going to put the 15 hp exhaust tube on it so I can do a better cleaning job then when I pull the powerhead. I figure a very liberal amount of anti seize grease plus freshwater only use from now on will make do until I can pull the powerhead. Thought?