Alpha 1 Shift Shaft maintenance

[rkvarner43]

I'm currently doing some much needed maintenance/repairs on my 1985 5.9 Seville with a 170MR (replacing a bad shift cable, bellows, water pump impeller, trim/limit senders). The play in the shift shaft seems ok, but should I go ahead and replace the bushings and seal since it's never been done (I've owned the boat since new).

thanks,
Ken

 

[IanFS]

Re: Alpha 1 Shift Shaft maintenance

I have an Alpha One which I overhauled last year and I would say whilst you've got the opportunity then I would replace as much as you can.
Don't know if this is much help Ken but my Mercruiser service manual includes the MR so I'm guessing the bell housing would be pretty similar.
I was able to install the seals from the Alpha One Gen 11. The old seals are really small and pretty ineffective, I took this photo and placed the old seal on the housing you can just see it lying on top to the left. The new one is enormous in comparison.

 

[rkvarner43]

Re: Alpha 1 Shift Shaft maintenance

Thanks for the info and picture. Now the diagram in the repair manual makes more sense. The new seal/bushing is larger and looks like it has a much better seal.



I love this forum!

Ken

 

[stonyloam]

Re: Alpha 1 Shift Shaft maintenance

but should I go ahead and replace the bushings and seal since it's never been done

A good idea, with OEM Mercruiser parts: #5 here: http://www.mercruiserparts.com/Show...0065.png&inbr=2203&bnbr=60&bdesc=BELL+HOUSING Look like this: http://www.mercruiserparts.com/showSpecialPicture.asp?pn=805041A2

 

[slag]

Re: Alpha 1 Shift Shaft maintenance

I have an Alpha One which I overhauled last year and I would say whilst you've got the opportunity then I would replace as much as you can.
Don't know if this is much help Ken but my Mercruiser service manual includes the MR so I'm guessing the bell housing would be pretty similar.
I was able to install the seals from the Alpha One Gen 11. The old seals are really small and pretty ineffective, I took this photo and placed the old seal on the housing you can just see it lying on top to the left. The new one is enormous in comparison.


View attachment 196108

I never understood what they were thinking with that updated upper bushing. Not only does it protrude well into the exhaust passage, it doesn't sit flush with the housing, so it looks like it is installed incorrectly.