Alpha One shift shaft drops low, won't stay engaged...

cadunkle

Petty Officer 2nd Class
Joined
May 8, 2006
Messages
128
I have an '89 Marlin Cobra with Alpha One drive. I swapped a new engine in and when I put the drive back on the shift shaft in the gimbal was knocked out of alignment. I removed the gimbal and got the shaft arm in the slot on the shift cable. The shaft/dog leg off the drive now drops down maybe 1/4", just a hair below the bit on the gimbal bellhousing shift shaft that it should sit in. Result is no shift. Drive shifts fine into gear when I move the shift shaft on the lower by hand, just won't stay up into the shaft off the bellhousing.

Any ideas why this might be? I have a feeling I will have to pull the lower to find out.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: Alpha One shift shaft drops low, won't stay engaged...

when I put the drive back on the shift shaft in the gimbal was knocked out of alignment.

You may need to be a little more specific.

If BOTH the shift control and lower unit shift shaft were positioned in FWD when you put the drive back on there's no way it could be "knocked out of alignment"

You have to use either a helper or a bungee cord etc to hold a little bit of "pressure" on the prop in the reverse direction to keep the shift shaft from moving as you slide the drive into place on the gimbal mount...

If it moved, you might have bent something by forcing it together....
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Re: Alpha One shift shaft drops low, won't stay engaged...

You will be pulling the lower unit to replace that SS washer that fell off the splined shaft.
 

cadunkle

Petty Officer 2nd Class
Joined
May 8, 2006
Messages
128
Re: Alpha One shift shaft drops low, won't stay engaged...

There was no washer above the shift shaft bushing in the lower unit. I don't see how it could ahve come off with the dog leg part of the shift linkage in the upper sitting on that shaft. I ended up picking a appropriate sized washer from my nuts&bolts bin and bolted the lower back on the upper. All seems well now.

I don't understand waht changed from before though. There still is no play in the shift shaft or in the linkage off the gimbal/bellhousing. I'll be keeping an eye on it but nothing seems wrong. Boggles my mind why the dog leg shaft drops now.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Re: Alpha One shift shaft drops low, won't stay engaged...

Heres how it disappears:
when you service a lower you install the washer and then some grease on the splined shaft, when the units go together the grease adheres the washer to the upper shoe and holds the washer in place on the shoe when your dropping the lower unit.Turn your back and the washer drops to the ground unseen.
 

havasuboatman

Ensign
Joined
Mar 5, 2009
Messages
904
Re: Alpha One shift shaft drops low, won't stay engaged...

There was no washer above the shift shaft bushing in the lower unit. I don't see how it could ahve come off with the dog leg part of the shift linkage in the upper sitting on that shaft. I ended up picking a appropriate sized washer from my nuts&bolts bin and bolted the lower back on the upper. All seems well now.

I don't understand waht changed from before though. There still is no play in the shift shaft or in the linkage off the gimbal/bellhousing. I'll be keeping an eye on it but nothing seems wrong. Boggles my mind why the dog leg shaft drops now.

Go to the adults only section at the top of the page, click on the repair manuals link, find your application, download, and look at the exploded view of your gear housing. (lower unit) I think you will see exactly what holds that shift shaft in place, and "what changed"
 

cadunkle

Petty Officer 2nd Class
Joined
May 8, 2006
Messages
128
Re: Alpha One shift shaft drops low, won't stay engaged...

Go to the adults only section at the top of the page, click on the repair manuals link, find your application, download, and look at the exploded view of your gear housing. (lower unit) I think you will see exactly what holds that shift shaft in place, and "what changed"

I studied the exploded diagram in the service manual before making my original post here. Care to enlighten me as to what changed since I clearly can't figure it out?
 
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