Alpha one gen one shaft length issue

[MTBoat]

got a decent looking alpha one gen one,,,, to replace the gen one on my 84 mercruiser 140.
I now see that the shaft length on the new one is about 8"+, the old one at 9"+.

Can I still use this unit as it, or is this a problem,,,, do I have to pull the old shaft to put on the newly aquired outdrive in order to use this outdrive and if so, is that done at the u-joint or???

 

[Bondo]

Re: Alpha one gen one shaft length issue

Can I still use this unit as it, or is this a problem,,,, do I have to pull the old shaft to put on the newly aquired outdrive in order to use this outdrive and if so, is that done at the u-joint or???

Ayuh,... Just change the forward most part of the shaft....

If ya use the short 1, the coupler will strip out in No time...

 

[Eric 3.7LX Alpha 1]

Re: Alpha one gen one shaft length issue

Alpha One wasn't there in '84. Have a look at the chart.

Your newer model is probably an Alpha One.

The yokes will have to be swapped at the u-joint and you should be all set. If not it won't go in the coupler at the back of the engine enough and can damage the splines.

 

[MTBoat]

Re: Alpha one gen one shaft length issue

thanks much.
The interesting part is that the unit I pulled off looks exactly the same as the gen one I got.
I assumed there was the pre-alpha look, the gen one look, and the gen II look....mainly identifying them from the upper gear box shape etc.
So, I do not know how they can look exactly the same (alpha one gen one look) and then have a different drive shaft length....but, I will change the shafts and seems it ought to go.