Mercruiser 3.0 L Alpha 1 shifting issues

[eavega]

Memorial Day weekend is in the books. Of course, a new problem had to crop up. First off, I am running a 1988 Stingray 176 SVB with a Mercruiser 3.0L SN 0B922590, Alpha One drive SN 0C302539. I am having shifting issues and I hope you all can help me troubleshoot it and hopefully get it fixed before the weekend.

What I am experiencing; On first startup, Motor will shift easily into reverse and forward gear. No problems, no excessive clunking or anything unexpected. After a few minutes of running (I was towing a tube where kids went flying, so I had to throttle down and then throw the boat in neutral while the riders climbed aboard) I found that if I went from forward gear to neutral, the drive acatually went into reverse. If I shifted into reverse, it stayed in reverse. If I shifted through neutral into forward, it went into neutral. I would try to go back into neutral and it would go into reverse. I then cut the ignition (remember I still had tubers in the water and they needed to get back on the tube so I needed to get the boat to stop moving) to stop the motor. When everyone was back aboard, I re-started the motor, and now I am in neutral. Shift into forward gear, and it went into forward gear. Went to neutral and it would go into neutral. Reverse, and it would go into reverse. Back into forward and ran for a bit. When it came time to go into neutral again, same bad behavior. Neutral put me in reverse, reverse kept me in reverse. Forward put me in neutral. Shut down the motor for a couple of minutes, everything is fine.

From what I have read online it seems that I may either be looking at a shift cable adjustment or replacement. I was wondering if anyone had a good concise guide to troubleshoot the shifting system? I have the motor manual but not the outdrive manual. Also, should there be anything else I need to be looking at? Maybe something binding or sticking and not moving through its full range of travel? Any help or advice would be greatly appreciated. I am hoping to have this back to fully functional by the weekend.

Thanks.

Rgds

 

[eavega]

Re: Mercruiser 3.0 L Alpha 1 shifting issues

Okay, so given the lack of any responses or suggestions, I did some further poking in the forum and other online locations, and found the YouTube video of how to adjust the shifting cables. I went into the boat and re-measured and reset the cables. What I found was that the lower shift cable had no slop, it measured exactly at 14mm as it was supposed to with the forward gear engaged and the cable end pulled out. The only thing I found was that the stud where the cable end mounts to (which is movable but only affects reverse gear) was loose, so I set it to the bottom-most position and tightened it down.

The upper shift cable, again, had no slop with a travel of 3 1/8" from forward to reverse. I did find that the barrel needed adjustment in order to set where it was supposed to. I don't know if it had slipped or something else happened, but I set it as the video indicated; let it fit, then turn it back 4 turns.

I haven't started the motor to see if everything is copacetic, but I did shift the motor into forward and turned the prop by hand, and it correctly locks the prop turning counterclockwise. Shifting into neutral allows the prop to spin freely. Shifting into reverse locks the prop turning clockwise. Since I wasn't having the issue with the shift interrupter stalling the motor I would assume that part was working and that the loose cable post on the shift plate as well as the mis-adjustment of the upper shift cable was causing my original problem.

As a precaution, I marked everything's position before I started adjusting, at least it was "somewhat" working before I started readjusting, so I can go back to previous marks if it totally doesn't work.


So, my question; would the loose cable post on the shift plate manifest the problem I was originally having? The "sometimes would shift fine, sometimes only giving reverse, but never stalling" ? Given my limited but growing understanding of the particulars of this motor, it would seem to me that if the lower shift cable post was loose, it is conceivable that it could slip to a higher position when doing a lot of shifting (like maneuvering away from a dock or stopping to recover a tuber/skier), thus allowing more travel when the motor was put in reverse, then not allowing sufficient travel back in the forward direction. Tightening that post down would allow the same amount of travel every time.

Thanks for any opinions/observations.

Rgds

Rgds

 

[Bondo]

Re: Mercruiser 3.0 L Alpha 1 shifting issues

So, my question; would the loose cable post on the shift plate manifest the problem I was originally having? The "sometimes would shift fine, sometimes only giving reverse, but never stalling" ? Given my limited but growing understanding of the particulars of this motor, it would seem to me that if the lower shift cable post was loose, it is conceivable that it could slip to a higher position when doing a lot of shifting (like maneuvering away from a dock or stopping to recover a tuber/skier), thus allowing more travel when the motor was put in reverse, then not allowing sufficient travel back in the forward direction. Tightening that post down would allow the same amount of travel every time.

Ayuh,.... Sounds reasonable to Me,...

 

[eavega]

Re: Mercruiser 3.0 L Alpha 1 shifting issues

For the record, re-adjusting the shift cables and tightening up the post on the shift plate solved the issue. Went out on Friday and did not have a single problem with shifting in and out of gear.

Rgds