Alpha One not going into reverse

WhiteH2O

Recruit
Joined
Jan 22, 2017
Messages
3
Hello, I've been fighting my I/O for a while now, and I've run out of ideas on my Merc Alpha One I/O on my 1988 Mirage 170 Magna Bow Rider.

The problem started with servicing my stern drive. When I put the stern drive back on, the shifting shafts weren't lined up well, and bent a little (you know, the little things that you have to be in FWD gear so that they will line up correctly?). I took it back off, lined them up and got it back on right. The shafts are a little bent (I think) but they seem to be fully engaging each other. Problem solved (I thought).

Then, it would shift into FWD, then stay in FWD when you shift into Neutral, and shift into N when trying to go into reverse. It would stay in N when you brought it back to N, and then shift into FWD when you shift into FWD.

"Okay, simple fix" I thought, and then I adjusted the shift cables. No joy. Forward is forward, Neutral is still a tad in fwd, and if you just barely bump it into REV it goes into neutral. If you go all the way into Reverse, it will just start catching, but not go into reverse. It will go back into a good neutral (no grinding) only when you just bump it past Neutral- just barely into FWD. It will solidly go into FWD when you move it all the way FWD.

Here is why I don't think it is a cable adjustment issue:

I disconnected the outdrive (lower) shift cable, and pushed it in all the way. Solidly in FWD. I started pulling it out, and it goes into Neutral. When I pull it out all the way, it doesn't go into Reverse; it does the same thing as when it was hooked up and I try to go into REV with the shift lever. You can hear the dogs knocking, but it doesn't grab.

Something is keeping it from going all the way into reverse. So where would you guys look? Would the slightly bent shafts keep it from shifting into Reverse? Am I missing something completely?
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,908
Yup, the shaft is bad, you need to replace them. They are a bit finicky and every thing has to be correct for it to work properly. While you are in there you may as well replace the shift cable and shift bellow, then you will know it's all good down there.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Did you seperate the unit for service or remove the unit whole
 

WhiteH2O

Recruit
Joined
Jan 22, 2017
Messages
3
I went out and played with it a little. I could reach back there and push it into Reverse and get it to catch; it didn't take much at all, but I could tell the alignment of the shafts is the problem. I tried to bend them back into place just out of curiosity, and broke the shoe part off the bottom of the upper shaft. Welp, replacing it was going to be the final answer anyways. So off to order parts I go.

Thanks everyone for the input. Bt Doc, I had the two halves apart to replace the impeller and such, but I don't think the issue came about until I had the entire unit off as one piece during later maintenance.
 

Baylinerchuck

Commander
Joined
Jul 29, 2016
Messages
2,726
Welcome aboard, sorry about your out drive trouble, but you came to the right place for help. Good luck!!
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
Just a quick question: when you mated upper case and lower case, did you make sure the lower was in Forward, kept in forward the whole time, and that the upper shoe was aligned straight fore and aft during and after the mating?
 

WhiteH2O

Recruit
Joined
Jan 22, 2017
Messages
3
Oh man, honestly, I did that over a year ago. It's been sitting for a while waiting for me to get time to fix it. I had watched multiple youtube videos prior to, and then had the best one up while doing it. I vaguely remember doing something like that. Playing with it and finding out that I just had to barely push it further to get it to engage into FWD makes me think the bent shafts (well, broken now) are to blame. If new parts don't fix it, I'll know where to look next!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
A few things come to mind. I've seen the bottom end of the upper shift shaft bent in such a way as to open up the 'shoe' slightly. You may need to remove the drive and close the shoe with a vice grip or somehting similar. It does sound like you have introduced more 'slop' in the system somewhere.

Have a look at my video on how to adjust the shift cable. The first part of the explanation is on check the amount of play in the shift system. That would be a worthwhile execise alone....

Shift cable adjustment

Chris..........
 
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