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Shift shaft allignment problem!

J

jobsonsplace

New member
I have a 2006 Alpha one gen2 drive on which I have removed the lower gear housing to replace the Impellor.

With the throttle in forward gear and the Impellor replaced I lined up the gear housing below the Drive shaft housing and mated the 2 halves making sure the shift shafts were alligned etc.

What has caused me concern and I need help about is to do with Upper shift shaft assembly.

Normally the saddle area of the U.S.S sits tightly over the RT angle section of the lower shift shaft, coupling both together for a gear change to occur.

My problem is if I push gently upwards against the U.S.S the shaft can raise vertically by 0.5cm which allows the upper and lower sections of the shaft to disengage, permanantly stopping me from engaging forward or reverse!

Urgent advice on this would be most welcome as we are due to launch next week. I don't want to find the coupling disengaging randomly.


The Drive shaft Housing has a serial no ow808552 and all the U.S.S bushes are fine.

Regards
Paul.
 
I wish I could help you, i'm new to I/O. I'm not sure if these have bearings or bushings holding them in place. If so I would check them to make sure they are packed correctly if not it may allow the shaft to make upwanted movement.... but just an idea man. I have not had to get into my outdrive yet. Good luck man.
 
Hi they have bushes, I understand, which are in good nick! And it's my first time as well, just changing the impellor should be easier.
many thanks
 
If I understand you correctly you are saying the U shaped shift shaft in the gimbal housing has too much vertical movement and will easily disengage the shift shaft in the outdrive. Correct?

If this is the case look closely at the bushing just above the U shaped end of the upper shift shaft. I have found several over the years where the bushing has moved UPward in the gimbal housing. If you look close at the bushing if this has occurred then you will see a difference in color in the bushing outer surface,

If all this is true, then just tap the bushing back down.

What i have done in one case due to location I was performing the repair, I used a sharp center punch and after tapping the bushing back down I hit the center punch into the aluminium of the gimbal housing surrounding the bushing a few times to force the alminium to grip the bushing better.

I hope this makes sense, I am only on my first cup of coffee.............
 
And it must be great Coffee, I will look into that idea asap.

I have noticed as well that the alum casing, surrounding the lower bush area, has a 1/4 " hole through which I can view the outer casing of the lower bush, I'm not sure why it's there but could use it to possibly lever the bush down.

A area which has caught my eye is from a page in the service manual (4b 35), it suggests that the Upper Shift Shaft is connected to the U.S.S lever, and it mentions a U.S.S lever screw.... If the screw was lose would the U.S.S be able to move vertically, causing my problem?
cheers
 
That hole is most likely for a 1/4 inch socket extension to get at a hose clamp.........It is not for the shift linkage.......


"""A area which has caught my eye is from a page in the service manual (4b 35), it suggests that the Upper Shift Shaft is connected to the U.S.S lever, and it mentions a U.S.S lever screw.... If the screw was lose would the U.S.S be able to move vertically, causing my problem?
cheers""""


I believe what you are refering to is the BELL CRANK, the part with the small wheel???????

If so this has a threaded pin, it is part screw and part pin, 10-32 threads in only 1/2 of the bell crank....carefull with this. If you mess up the screwdriver slot to try to get the pin out you will have to drill it out and retap the threads..............this part is stainless steel.......requires cobalt (pure, not coated drill bits)

Also please try to use full english to describe your things, ACRONYMS SUCK!
 
The only way to see the problem is to remove the upper from the bell housing. You will get a full view of the USS and the bushings. Sounds like the set screw has come loose.
 
DId I missunderstand his question????

was he saying the U shaped end was not at 12:00 and it may be due to the screw loosening? I thought he was saying the U shaped part was not fitting correctly with the shift shaft from the lower..............if I miss understood ..my bad............need more coffee before reading these things........

OK i just reread and he said what I thought he said, not that the screw could also be loose.................
 
kghost said:
DId I missunderstand his question????

was he saying the U shaped end was not at 12:00 and it may be due to the screw loosening? I thought he was saying the U shaped part was not fitting correctly with the shift shaft from the lower..............if I miss understood ..my bad............need more coffee before reading these things........

OK i just reread and he said what I thought he said, not that the screw could also be loose.................
Click to expand...

The way I understood him was that the Upper Shaft had vertical movement and he was able to lift the upper shaft off of the lower after the lower unit was installed. Worn bushings will give you side to side movement, up and down is usually the set screw.

Maybe we both need more coffee.
 
Last edited:
Hi Chris, Are you saying that the set screw ( or lever screw from my service manual) secure the Upper Shift Shaft in place and if loose will allow the shaft to move up/down?
 
jobsonsplace said:
Hi Chris, Are you saying that the set screw ( or lever screw from my service manual) secure the Upper Shift Shaft in place and if loose will allow the shaft to move up/down?
Click to expand...

That is what it sounds like the problem is to me.
What I am definitely saying is, remove the upper unit from the Transom assembly and you will see what is actually worn or loose. Six 5/8 nuts and the trim piston rod and the upper is off.

That's what I would do.
 
Docksidemarineservices said:
The way I understood him was that the Upper Shaft had vertical movement and he was able to lift the upper shaft off of the lower after the lower unit was installed. Worn bushings will give you side to side movement, up and down is usually the set screw.

Maybe we both need more coffee.
Click to expand...

Yes Chris I agree, BUT I have come across several where the bushing itself has moved UPWARD in the bellhousing approximatly 1/8 inch.
Poor machining tolorances I guess or poor bushing outside diameter tolorances..........


If the screw has come loose that will be an easy fix so lets hope this is it.............
 
Here is a better picture i used for another post a while back.

You can see most of the parts concerned with your issue.

Item 5 is the bushing I am refering to and the BELL CRANK is where the threaded pin is located.

Hope this helps.
 
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