Mercruiser 5.0 Alpha one has no reverse and stays in gear

[skoboten]

The boat only goes in gear (forward). Try to take it out of gear (neutral) and it stays in forward. Reverse is forward also. You have to kill the engine and re-start to take it out of forward. Somebody told me to change the lower unit oil, but I'm thinking it's more of a linkage/shift cable issue. I'm not the most handy guy, but I can't find an honest boat mechanic in the Birmingham, AL area.

 

[Eric 3.7LX Alpha 1]

Re: Mercruiser 5.0 Alpha one has no reverse and stays in gear

Read this link from the sticky at the top of this forum:
HOW TO: How the Shift Interrupt system works
http://forums.iboats.com/showthread.php?p=1930449#post1930449

What year or even better serial#'s

 

[Fishermark]

Re: Mercruiser 5.0 Alpha one has no reverse and stays in gear

Manually engage the shift interrupt switch and see if it kills the engine. Sounds like it is either not working, or has been disconnected. (If you aren't sure where it is, look at where the shift cable connects to a plate on the engine somewhere.

 

[bdefender]

Re: Mercruiser 5.0 Alpha one has no reverse and stays in gear

I have a 1988 4.3L Alpha One and I'm having the exact same symptoms.

The thing that's confusing to me about this is that reverse won't engage even from neutral. If I start the engine it will go into forward but then won't come out of forward until I turn the engine off. This seem consistent with the cutout switch not activating properly to shift out of forward.

The part I don't understand is, when starting from neutral, moving the remote control to reverse moves the shift cables but it remains in neutral, the engine just revs. Does the cutout switch need to activate to shift out of neutral or does it only engage when shifting out of forward and reverse?

Just to give the full story, I also recently replaced the remote control and remote cables because the remote control was jamming up. It was very difficult to move the lever into reverse and sometimes it would jam and not move the shift cable into reverse. It's likely that when I installed the remote control I didn't properly adjust the remote shift cable. I did have one successful voyage though. I had to slightly adjust the cable once in the water the first time so it would move into neutral when the remote control was in neutral, but it was working great at that point.

(I promise to post back with the final solution when I get this fixed!)

 

[franktrav]

Re: Mercruiser 5.0 Alpha one has no reverse and stays in gear

if the remote is adjusted properly........and you cannot shift to reverse.......
may be a bad lower shift cable

 

[bdefender]

Re: Mercruiser 5.0 Alpha one has no reverse and stays in gear

My problem ended up being the shift shaft. The lower shift shaft wasn't mating to the upper shift shaft. I recently had the impeller pump and some seals replaced in the lower unit and I guess the shop failed to reassemble everything properly. I took it back to the shop and they took care of it.

It seemed to me like the lower shaft was missing a retainer because it would move up and down freely. Now that its fixed it stays properly mated with the upper shaft.

 

[ktbarrentine]

Re: Mercruiser 5.0 Alpha one has no reverse and stays in gear

My problem ended up being the shift shaft. The lower shift shaft wasn't mating to the upper shift shaft. I recently had the impeller pump and some seals replaced in the lower unit and I guess the shop failed to reassemble everything properly. I took it back to the shop and they took care of it.

It seemed to me like the lower shaft was missing a retainer because it would move up and down freely. Now that its fixed it stays properly mated with the upper shaft.

Yours is a typical problem and solution (easily found and fixed through thread searches). Congrats on getting it fixed, and on successfully hijacking skoboten's thread! Now, if we can only get him to come back and tell us what happened with his problem....:facepalm: