Alpha One Gen 1 Shift Shaft Seal

[todhunter]

I'm rebuilding my Alpha One Gen 1 transom assembly (SN 0B667146) and ordered new seals and gaskets for it from Mercruiser Parts. I was going to reassemble the new shift shaft seal into the bell housing and the part I ordered (PN 26-8164641) won't fit. I've already thrown the old seal out, so I don't have it to measure for comparison, but the new seal has an OD of 0.75" and a height of 0.25". The "pocket" on the bell housing where the seal sits just below the upper bushing is measuring about 0.62" diameter and 0.125" deep. Mercruiser Parts said their files show this should be the correct seal and they can't advise me any further.

Can someone help me out with the correct PN?

Here's a picture of the old seal. I took the picture so I could reinstall the new one in the same orientation, but I no longer have the old seal.


Here is the new seal I was sent that doesn't fit. Comparing it to the picture above, you can tell it's bigger around and thicker than the original seal.

 

[Rick Stephens]

Merc changed that bushing to one that the seals are no longer contained inside but in a larger part of the bushing. Looks like the picture. You should switch to that setup, it is not expensive. I think the part number is 23-805041A2

 

[todhunter]

**edit** after googling the PN you provided, it looks like the wide part of the new bushing you're showing hangs down into the exhaust cavity and that's where the seals go. I'll order the part and replace it. Thanks for the quick response.

 

[Chris51280]

that is correct. done it too. only changed the upper since the seal was the important part and the bottom bushing was still ok.

 

[todhunter]

that is correct. done it too. only changed the upper since the seal was the important part and the bottom bushing was still ok.

Pretty easy to hammer out the old bushing and hammer the new one in? I plan on trying it without buying the "special tool".

 

[Rick Stephens]

A long 3/8th bolt through from the bottom, put the nut on, then a washer and use it to drive in the bushing. Easy peasy.

 

[Chris51280]

i used a threaded rod. some washers, some nuts. a socket. you will figure it out. I wouldnt hammer it since this is cast aluminum and one slip and you are in to buy a new bell housing. the worst part is to get the shift arm off. the little set screw is glued in. too much heat and you melt the plastic roller.

 

[todhunter]

Thanks for the tips guys. Shift shaft is already out, and I used some 3/8" threaded rod and an 11mm 1/4" drive socket to hammer out the original bushing - worked like a charm. It didn't even take much force to knock it out. I've ordered 23-805041A2 to replace it with.

 

[Kubaat3lover]

Can anyone provide any photos from this operation please? thanks!

 

[todhunter]

I'll try to snap some pics tonight showing what I've got done so far.

 

[todhunter]

@Kubaat3lover - I mocked it back up to show what I did to drive the old bushing out. I just hammered on the top of the threaded rod lightly and the bushing came right out.