Seized shaft removal 1980-7.5 hp Johnson

dave pollock

Recruit
Joined
Oct 23, 2011
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3
While servicing my lower leg and winterizing I have found the propshaft to be seized in the head and one of my coil packs has wept . The motor runs well and shifts great . I am wondering -do I try a slide hammer-or is there a better way? Also how to decipher the coil issue J8RCSS motor. Thx.
 

boobie

Supreme Mariner
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Nov 5, 2009
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20,826
Re: Seized shaft removal 1980-7.5 hp Johnson

Are you talking about propshaft or drive shaft???
 

dave pollock

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Oct 23, 2011
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Re: Seized shaft removal 1980-7.5 hp Johnson

thx driveshaft...
wondering about heat -a press or -slidehammer
 

boobie

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Re: Seized shaft removal 1980-7.5 hp Johnson

Is it only the d/s stuck in the p/h or is the whole l/u still on it??
 

James R

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Feb 1, 2007
Messages
2,660
Re: Seized shaft removal 1980-7.5 hp Johnson

If the shaft has pulled out of the lower unit, which they very often do when you heave on the lower to free it, sit the motor on the fly wheel with shaft pointing up and run some PB Blaster down the shaft. Try jiggling the shaft to get the Blaster into the splines. Leave it overnight. Jiggle it some more and give it more PB. Leave it some more then carefully clamp a good vice grip on an unimportant part of the shaft so as to tap the vice grip and shaft away from the PH. Be patient and try not to damage anything.
Once out clean the splines and use a waterproof grease on the splines.
 

boobie

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Re: Seized shaft removal 1980-7.5 hp Johnson

If this is the case you may want to mix up some ATF and Acetone 50/50 and try that. PATIENCE !!
 

dave pollock

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Joined
Oct 23, 2011
Messages
3
Re: Seized shaft removal 1980-7.5 hp Johnson

Thank you both -for your suggestions.....I will let you know in the coming days how this old girl responds to a little persuasion. The lower leg does in fact come off with the gear selection rod-that drive shaft needs some love....here goes.
 

Haffiman

Commander
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Dec 17, 2009
Messages
2,454
Re: Seized shaft removal 1980-7.5 hp Johnson

The easiest is to remove the powerhead from leg with the shaft.
Clamp it in a vice, power head down.
Then keep pouring all the funny mixes you get adviced to pour.
After some time, carefully try to knock the PH off the shaft.
However be aware that you might end up with a spline-less crank.
If you do not want to experience the latter, this is a naughty emergency way:
Cut the shaft about 1-2" above the water pump.
Weld on a socket on upper part, grind a square on the lower that fits into the socket. (3/8).
Be sure the total length of the shafts are the same as the old 1-piece shaft.
The above without warranty, but have rescued 'me' quite some times. Cheaper than replacing the crank.
 

boobie

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20,826
Re: Seized shaft removal 1980-7.5 hp Johnson

I've got an old saying that I learned yrs ago. " Do it right, or don't do it at all". And then there are cobblers.
 

boobie

Supreme Mariner
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Nov 5, 2009
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20,826
Re: Seized shaft removal 1980-7.5 hp Johnson

TN-25, that's a great idea. Learn something new every day.
 

F_R

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Jul 7, 2006
Messages
28,195
Re: Seized shaft removal 1980-7.5 hp Johnson

So happens that just this morning I removed a stuck drive shaft (powerhead off). I did it by fabricating a clamp collar for the shaft and beating it out with a slide hammer after a long soak in Kroil.

However---no surprise, the splines in the crank are almost gone. RUST is why, and why it was stuck in the first place. Well actually the original cause was lack of grease and a missing o-ring. For lack of a 10c o-ring, a motor is lost.
 
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