10 hp Johnson (QD-24 1963) converting to short shaft

[riverjet502]

I have a long shaft 1963 10 hp Johnson. I want to convert it to a short shaft. I have a short drive shaft and the short shaft water pump housing with the correct copper cooling line. My question is this... When I go to unbolt the lower unit will the drive shaft just slip out of the spines on the power head or is there a clip holding it onto the power head? I don't have a manual and was wondering if someone might be able to shed some light on me or point me towards a diagram or a sevice manual...

 

[F_R]

Re: 10 hp Johnson (QD-24 1963) converting to short shaft

To remove the lower unit, merely disconnect the shift rod through the oval access hole cover on the side of the leg, about half way down, remove the 4 bolts and drop the gearcase down and away.

Remove the water pump housing and the drive shaft will pull out of the gearcase

Make sure you install the short impeller housing spacer and o-rings

The biggie is the shift rod. If it is a factory long shaft it will have a long shift rod which must be replaced with a short one, requiring disassembly of the gearcase. OR, if you are careful, cut exactly 5 inches off of it and file a notch in exactly the right place 5" down from the old one for the shift rod connector screw.

If it is a factory short shaft that was converted to long, it may have a long shift rod connector. If that's the case, you need a short one to replace it with, no shift rod modification needed in this case.

Make sure you have a good or new o-ring for the groove at the top of the drive shaft. This is important! Smear some grease on it before assembly. Also smear some on/in the water tube grommets so the tube slips in easy.

When assembling, use a flashlight to look in the access hole and make sure the notch in the shift rod lines up exactly with the screw hole. If the screw threads rub on the notch edges it will strip the threads off the screw every time. Then it falls out the first time you get beyond rowing-back distance from the dock.

Don't fear, it's really a pretty easy job

 

[OBJ]

Re: 10 hp Johnson (QD-24 1963) converting to short shaft

Welcome reverjet to iboats on this New Years Day!!

I'm thinking there is a spring pin through the drive shaft that holds the blocks lower seal assembly in place. What you do is drop the lower unit until you feel the spring pin catch. Then turn the drive shaft a little at a time till the spring pin aligns with the slot up in the midsection which will allow you to drop the lower unit the rest of the way down. Not the position of the pin when the lower unit is out so you can align it right when you reassemble the unit. The blocks seal assenbly won't fall out so you don't have to worry about that.

 

[OBJ]

Re: 10 hp Johnson (QD-24 1963) converting to short shaft

Got there before me FR.....dd

 

[F_R]

Re: 10 hp Johnson (QD-24 1963) converting to short shaft

OBJ, You are thinking of a 6hp with the roll pin in the shaft. Does not apply to the 10hp.

 

[riverjet502]

Re: 10 hp Johnson (QD-24 1963) converting to short shaft

Thanks guys for the good info. I appreciate it... This should be pretty simple. I have a complete short shaft lower unit in working condition that I am planning to swap and keep the 5 inch tower extension bolted to the present lower unit. Thanks for the tip on the "O" ring. The lower unit I plan on swaping in doesn't have a "O" ring on the drive shaft. That was why I was wondering what that grove was for. Now I need to figure out the proper "O" ring size.

Thanks again !!!!!

 

[OBJ]

Re: 10 hp Johnson (QD-24 1963) converting to short shaft

Thanks FR...d