35hp '59 Big Twin Shaft Conversion

[timmeraw]

Hello,

I want to convert my '59 35HP Big Twin from Long to Short shaft. I found someone with a '64 Rude 40 HP looking to do the opposite.

The question.....are the drive shaft, shift rod, and water pipes compatable for this swap of ours? Also...how do we both remove the shift rod from the foot of our engines?

I also assume that the drive shaft will just pull out of the foot on both(mine seems to easily lift when I tried when
replacing the impellar though I didn't totally remove it).

Thanks,

Tim

 

[tmcalavy]

Re: 35hp '59 Big Twin Shaft Conversion

Are you talking about a 59 E-rude Big Twin or a 59 Johnson Sea Horse 35 hp (your motor)? You should be able to swap unless the 64 has an electric/selectric shift LU, if both have the same number of water tubes (2), and same number of splines/gooves on top and bottom of driveshaft. The guy going to long shaft will also need a longer shift shaft connector. The shift rod doesn't need to be removed, the shift shaft connector needs to be changed.

 

[timmeraw]

Re: 35hp '59 Big Twin Shaft Conversion

Are you talking about a 59 E-rude Big Twin or a 59 Johnson Sea Horse 35 hp (your motor)? You should be able to swap unless the 64 has an electric/selectric shift LU, if both have the same number of water tubes (2), and same number of splines/gooves on top and bottom of driveshaft. The guy going to long shaft will also need a longer shift shaft connector. The shift rod doesn't need to be removed, the shift shaft connector needs to be changed.

Yes my Big Twin is an Evinrude...... when U say shift cable connector I am not really clear. My lower shift rod connects to the upper shift rod via a brass connector with two bolts...one grabbing the lower rod and the other grabbing the upper rod(via a small grove in both of their ends). This is located thru a small square inspection port on the upper part of the leg. You say I don't need to take out my shift rod but it will need to either be cut off or replaced with a shorter one because minus the 5" extension it will be too long.

I would love to not have to take the foot/skeg apart but if so I will.

 

[lindy46]

Re: 35hp '59 Big Twin Shaft Conversion

The shift rod length is the same for either long or short shaft. The difference is the brass shift rod coupler (shift shaft connector that TM is talking about). The long shaft coupler is about 6 inches long and the short coupler is about an inch long. You will have to exchange couplers along with the water tubes, which are 5 inches longer on your motor. And of course, the driveshaft. No need to take the lower unit apart, just drop it. You'll have to take the water pump housing off to get the driveshaft out - it will just pull out. You'll also need to exchange that long bolt at the back of the motor which goes in from the top - yours is 5 inches longer than the bolt on a short shaft motor. That should do it!

 

[timmeraw]

Re: 35hp '59 Big Twin Shaft Conversion

The shift rod length is the same for either long or short shaft. The difference is the brass shift rod coupler (shift shaft connector that TM is talking about). The long shaft coupler is about 6 inches long and the short coupler is about an inch long. You will have to exchange couplers along with the water tubes, which are 5 inches longer on your motor. And of course, the driveshaft. No need to take the lower unit apart, just drop it. You'll have to take the water pump housing off to get the driveshaft out - it will just pull out. You'll also need to exchange that long bolt at the back of the motor which goes in from the top - yours is 5 inches longer than the bolt on a short shaft motor. That should do it!

Ok...thanks for taking the time but I gotta tell ya that there is no way that the lower shift rod is the same on a long and short shaft. It connects to the upper shift rod with a "coupler". Maybe you are thinking of another model but this long shaft coupler is about 1" long and brass. It has openings on top and bottom for the two shift rods to come in and two bolts...one each to hold/couple the top and bottom rods via the knotch in each. This "coupler" is only a few inches above where the foot(on a short shaft) or the foot and 5" extension on a long shaft bolt together. You access the coupler to loosen/tighten from the side of the leg via a small inspection window. Without a shorter bottom shift rod it will go ....well I guess 5" up into the leg past the coupler.

Do you get what I mean? I will have to take a picture later I think but it just has to be a shorter lower shift rod.

 

[jasper60103]

Re: 35hp '59 Big Twin Shaft Conversion

yea, I thought they would have used the long coupler for LS as well, but I guess they didn't do it on that model year.
See pic of my '62 28hp long shaft. Notice the long coupler.

 

[1946Zephyr]

Re: 35hp '59 Big Twin Shaft Conversion

Yea, I seen the same coupler when I changed out a few of these. All shift rods coming out of the lower units should be the same length, from what I have seen. You should only need the coupler, shaft and water tubes.....and of course the longer bolt.

 

[timmeraw]

Re: 35hp '59 Big Twin Shaft Conversion

Nope...my lower shift rod is much longer than that one in the picture....5 inches to be exact and the couple is the same but for it is 5 inches shorter and only 1" long.

So...back to my question....how does one remove the lower shift rod to replace it with a shorter one...or is the answer to cut it off and cut a notch into it? I have to believe that there are shorter ones out there.

Look at the attachments and you see the 1" coupler thru the inspection window and also notice just how much too long the shift rod is extending well past the coupler(and of course the drive shaft and tubes are too long also).

 

[lindy46]

Re: 35hp '59 Big Twin Shaft Conversion

Did some checking and looks like that was a factory long shaft motor with a longer lower shift rod. To change it out, you will need to remove the skeg from the bottom of the lower unit. You'll have to remove the Phillips head screw/pivot which goes through the shift yoke. Then the lower shift rod will just pull out from the bottom. You could cut it off and notch it, but cut EXACTLY 5 inches off. But the guy you're trading with will need the longer shift rod, or else he will have to find a long brass coupler to use with his existing shift rod. Those long couplers aren't that easy to find. I have an extra (short) lower shift rod - if interested, send me a PM. I think I may have a long brass coupler also - I'd have to look thru my stuff.

 

[tmcalavy]

Re: 35hp '59 Big Twin Shaft Conversion

Never seen one like yours, but as noted...just swap shift rods from the LU's...very easy to remove from the shift yoke in the gearcase. Most have equal length shift rods and the longer connector...you must have a transition model...interesting. You can make a long coupler in a pinch.