Short Yoke or Long Yoke?

[JustinF]

I have a 1987 Sea Ray Seville 17 I/O that I bought from a boat "salvage" place a little while back. I'm in the process of rebuilding the 3.0L and wanted to make sure I have the correct size yoke on the drive unit for when I put it all back together (I don't want to risk ruining a coupler). I know that the drive unit on the boat is not the original one (it's older), so I wasn't sure how to tell if it has the proper length yoke for my application. I measured the yoke that is on there now and it is 8 1/8". But when it was on the boat prior pulling the engine, you could see about 1/2 - 1" of splines showing behind the coupler and I'm concerned that it isn't long enough and I should have the 9 1/2" yoke.

My boat details:
1987 Sea Ray Seville 17 I/O
3.0L Mercruiser (s/n: B555134)
Transom Assy (s/n: OB474957)
Original Drive Unit (s/n: OB656027)
Drive unit on boat now (s/n: 4326341)


BTW, please bear with me if this topic has been discussed ad nauseum. I've been searching for a few days and haven't been able to come up with an answer to my question, so if this has already been answered, please post a link.

Thanks in advance for all your help!
Justin

 

[Bondo]

Re: Short Yoke or Long Yoke?

1987 Sea Ray Seville 17 I/O
Transom Assy (s/n: OB474957)

Ayuh,......

That Should be an Alpha,.... Which uses the Long shaft, 9+".......

Only the Pre-Alpha, In-line motors use the 8+" shaft......

 

[JustinF]

Re: Short Yoke or Long Yoke?

Thanks for the quick reply

Looks like I'll be replacing the yoke and the u-joints while I'm at it. When replacing the u-joints, is it standard procedure to replace the socket that the u-joints go into as well?

Justin

 

[Bt Doctur]

Re: Short Yoke or Long Yoke?

The center section is ok IF it is undamaged.It is not normally replaced unless the U joint has exploded.

 

[Don S]

Re: Short Yoke or Long Yoke?

When replacing the u-joints, is it standard procedure to replace the socket that the u-joints go into as well

Somehow I would bet he is referring to the bearing caps on each of the 4 corners of the ujoint cross piece, if so, then yes, they come with the ujoint.

One other problem, if you have bought some used drive and it has the wrong length shaft, it probably also has the wrong gear ration for whatever you are trying to do.