Alpha One shift cable adjustments - adjust to spec, or leave it working correctly?

eavega

Lieutenant
Joined
Apr 29, 2008
Messages
1,377
Sorry if this is a long read...

Last year before the boating season, I had a mechanic replace the lower shift cable due to problems with the outdrive not shifting reliably into neutral (It would stay in forward gear when shifting from forward to neutral sometimes). All last season, while it now reliably shifted from forward to neutral, shifting into forward didn't feel right. Rather than the nice solid "thunk" of the gears engaging, I would occasionally get a "rat-tat-tat-thunk" engagement of forward gear. I lived with it for the season thinking that it may be the new shift cables (actually ended up replacing the remote shift cable during the season. My throttle cable came apart in June, so since I was already replacing that cable, and the lower shift cable had been replaced, I should just do ALL the cables) not having enough travel due to needing to stretch out just a little bit. I did verify that all the cable measurements were within spec according to achris' video (an invaluable tool. Thanks so much for posting that achris).
Fast forward to last weekend. Getting the outdrive back on the boat in preparation for this season. Boat has been in forward gear all winter since the outdrive was off. After I re-assembled I wanted to verify that everything was as it should be, so I checked prop movement in each gear. Neutral the prop spins freely, Reverse locks the prop clockwise. Forward, didn't QUITE lock the prop. I would spin CCW and you would here a slight "clack-clack-clack" as if the gears were touching but not engaging. Now if I removed the lower shift cable from the shift plate and push in, then the prop locks as expected. If I then measure out the lower shift cable adjustment to 6" per achris' video and replace the shift cable on the shift plate and then test the gear engagement, once I shifted through the gears it would then go back to not-quite-engaging in forward gear. I lengthened the cable by moving the brass barrel an additional 1/4", and now I get correct engagement in forward, neutral, and reverse (with the motor off. I haven't tested in the water with the motor running yet).

so the question is, should I leave it as it is now working, or should I put it back into specification and look to another reason that forward is not engaging fully (like worn gears).

Thanks in advance for any insight or information.

Rgds

E
 

Fun Times

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Staff member
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May 16, 2009
Messages
8,776
When you are checking and adjusting the lower cable to 6 inches, is the stern drive down in the lowered position? If not you'll get a false adjustment.

Typically if you have to go outside the 6 inch range on the lower cable then something else isn't 100% such as the lower cable isn't seated in the bell housing correctly or the threaded stainless tube by the brass barrel isn't screwed all the way in, shift shafts worn at bell housing, the slide adjustment at the shift plate is off or the new cable from shifter is misadjusted or has to much play, the aluminum shift slide that sticks out of the bell housing could be to tight or to loose adjusted by the set screw or packed with to much grease or debris in the bell housing cavity. Hopefully there's not anything wrong with the shift spool assembly inside the lower unit of the drive such as the spring getting worn-out, etc.

The cable from the shift handle to the shift plate should adjust out to the adjusted 6 inch lower cable. Since you were able to get the prop to lock both ways (with the drive down?), it's probably going to work okay as the cable may have just needed the fine tuning as cable end play tends to vary between some cable manufacturers.

Be sure to let us know your final out come, good luck.:)

Below are some other helpful guides if needed,
http://www.mercstuff.com/shiftcable2.htm
https://www.perfprotech.com/store/app_themes/ppt/images/tech-specs/alpha-shift-adjust.pdf
http://sterndrives.com/replace_alpha_shiftcable.html
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
I don't know why, but drive work that shouldn't effect the shift adjustment sometimes does. Redo the complete adjustment procedure and be on the safe side.
 

eavega

Lieutenant
Joined
Apr 29, 2008
Messages
1,377
When you are checking and adjusting the lower cable to 6 inches, is the stern drive down in the lowered position? If not you'll get a false adjustment.

Hmm, so I was still in the process of re-installing the outdrive, and the trim rams were not installed yet. I would assume it would put my drive in about the lowest position possible, although that might not necessarily be the case. In any case it should've been in a down position.

A lot of other stuff to check out. As I didn't do the work on the lower shift cable, I may take it back to the mechanic to re-evaluate. I'll verify my measurements on the remote shift cable to make sure that is not the problem. Thanks so much for the input.

-E
 
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