Shift from forward to neutral binding up?

[redgoat]

Again this year, after my first time out today, my throttle lever is not going into neutral as it should. There feels like some binding up as I try to get it there. If I wait a few moments, it likely will go into neutral smoothly. I had this problem in '07, and in '09. Each repair was about $600 each time (w/ different repair shops). Aside from making docking the boat a real challenge the boat runs fantastic for a 44-year-old Sea Ray with a 120hp, 153cu.in Mercruiser 4cyl. I hate to "force" the shift lever into neutral but waiting for something to happen to make the shift possible is annoying. Both repair shops replaced shift cable, shift slide, lever and cam, and other assorted parts. Shouldn't these shift cables last more than a couple of seasons? Any opinions on what's wrong and what I might do to correct it?

 

[Eric 3.7LX Alpha 1]

Re: Shift from forward to neutral binding up?

Depends. IF water is getting to the cable they can go quicker. Has the shift shaft bushings in the bellhousing ever been upgraded to the newer style? Here is a photo of Fishermarks done. They are the 2 brass bushings on either side of the shift shaft. There is a seal pressed into the upper one. which keeps water out of where it shouldnt be.

So after the shift cable was replaced in the past, everything was good for the season?

 

[atistang]

Re: Shift from forward to neutral binding up?

is your shift interrupt switch working?

 

[redgoat]

Re: Shift from forward to neutral binding up?

Re shift interrupt switch. Y'know I noticed a small, unpluged electric line in the engine compartment this spring as I was summerizing my boat. This electric connector appears to be one of an identical pair of connectors that plugs into something. I did not know what to do so I pluged it into the available connection right next to the one that was already plugged in. Both plugs are part of the same cable. Do you think if I unpluged that one side it might correct the problem?

 

[Don S]

Re: Shift from forward to neutral binding up?

You may not have lower shift cable problems. It could be something else. The shift cable from control to engine, shift interrupt switch intermittent or slow activating (Thick heavy grease????), or things way out of adjustment, drive shift spool worn out. Do you have an OEM cable or aftermarket? Old style or new? If new style, was the bellhousing tapped out properly? If not, it will bind up big time.
Is the shops you took your boat to Mercruiser dealer, or just some auto mechanic with a shingle out thinking he can do anything? I have worked for shops like that. I have posted more info on this forum in the past few years, than those kind of shops even know about.

 

[redgoat]

Re: Shift from forward to neutral binding up?

'07 repair was a Sea Ray dealer, '09 was a different marine repair shop. Seems strange that it worked fine last fall and now it's back to binding up--in spite of the fact that it is used less than 10 times per season. I guess I will have to take it back to the last repair shop and inquire about what was done to correct it 2 years ago. By the way, where is the location of the shift interrupt switch, what does it do, and is there anything I might do to check its proper functioning?

 

[SeattleMatt]

Re: Shift from forward to neutral binding up?

Does it come out of gear easily if you turn the engine off? You should be able to manually activate the lever on the shift interrupt switch and it should kill the motor. If it does not, then the switch is faulty. The drive gears are cupped and designed to hold the unit in gear unless the motor is killed.

 

[redgoat]

Re: Shift from forward to neutral binding up?

With motor off, the lever shifts easily into forward and nicely back into neutral into its detent. Same for neutral to reverse and back. Could that unplugged electric line be part of my problem? Should I have left it unplugged like I found it?

 

[SeattleMatt]

Re: Shift from forward to neutral binding up?

Where you able to locate the shift interrupt switch and try to see if it kills the motor? I wouldn't worry about the wires for now, just check the switch basic function.

 

[Eric 3.7LX Alpha 1]

Re: Shift from forward to neutral binding up?

Read this from the Adults Only Sticky at the beginning of this forum-
HOW TO: How the Shift Interrupt system works

http://forums.iboats.com/showthread.php?p=1930449#post1930449

 

[redgoat]

Re: Shift from forward to neutral binding up?

I don't know where the switch is located or what it looks like. The prop did stop spinning today when I finally got the throttle into neutral. The fact that it shifts smoothly with the engine off leads me to now believe that it is NOT the cable but perhaps, like you suggested, the shift interrupt switch. Could it be dirty and just in need of a cleaning? Really appreciate your help but need some guidance in locating the switch. Had wife move throttle while I watch cables move but could not see any switch being activated.

 

[Eric 3.7LX Alpha 1]

Re: Shift from forward to neutral binding up?

You will have 2-cables coming from the shifter, one for the throtle the other to shift the outdrive.

The throtle cable runs to the carb, the shift cable will connect to the engine on a bracket where the shift interruptor is located. The shift cable from the outdrive attaches to that same bracket on a different mount.

What do you have for a manual for your engine/drive?

 

[redgoat]

Re: Shift from forward to neutral binding up?

Thanks Eric for posting Don's "How To". Very informative. From reading this information on how the shift interrupt system works I think this is likely my problem. These forums are great.

 

[redgoat]

Re: Shift from forward to neutral binding up?

I will look again in the engine compartment to locate shift interruptor. I have the 2 volume original Mercruiser Service Manuals from 1967. I will reference them and hopefully pinpoint my problem. Thanks again for your help.

 

[atistang]

Re: Shift from forward to neutral binding up?

your shift interrupt should look like this (the little metal tab coming out of a box with wires going to it) if you push that tab in with the engine running it should kill it. if it doesn't then the switch is bad or there is a problem in the wiring

 

[redgoat]

Re: Shift from forward to neutral binding up?

I FOUND THE SWITCH! Thanks so much for the excellent photo. I will take your advice today and check out its operation. If I find it defective, are these switches still available? An earlier post said that I would need to upgrade to a newer design. My boat is 44 years old and could quite possibly have the original switch.

 

[redgoat]

Re: Shift from forward to neutral binding up?

One photo shows the shift interruption switch. With the muffs on and the engine running the roller cam does not move at all when the throttle cable is shifted from neutral to forward, forward to neutral, and from neutral to reverse, reverse to neutral. It just stays in its little notch. Further, while doing the above mentioned shifting, the other photo shows a throttle cable linkage that does not move either. I would think the cable would move DOWN in the slotted opening at some point. But it stays put at all times while at idle on my driveway. Is this normal? Could my problem be cable related as well as possibly shift interruption related?

 

[atistang]

Re: Shift from forward to neutral binding up?

i think that cable in the slotted area is the adjustment, it looks to be adjusted as far as it can go, if you slide it back the other way then it will not move as much

did you watch the roller and have someone shift it? or did you shift it, then walk back and look at it?

 

[wca_tim]

Re: Shift from forward to neutral binding up?

My understanding is that you won't see the problem in your driveway on muffs - the resistance to coming out of gear comes from the load - a load you don't have until you're in gear and the prop is turning against resistance... Make sense?

One photo shows the shift interruption switch. With the muffs on and the engine running the roller cam does not move at all when the throttle cable is shifted from neutral to forward, forward to neutral, and from neutral to reverse, reverse to neutral. It just stays in its little notch. Further, while doing the above mentioned shifting, the other photo shows a throttle cable linkage that does not move either. I would think the cable would move DOWN in the slotted opening at some point. But it stays put at all times while at idle on my driveway. Is this normal? Could my problem be cable related as well as possibly shift interruption related?

 

[Fishermark]

Re: Shift from forward to neutral binding up?

With the muffs on and the engine running the roller cam does not move at all when the throttle cable is shifted from neutral to forward, forward to neutral, and from neutral to reverse, reverse to neutral. It just stays in its little notch. ....Is this normal?

Yes - as mentioned, it shouldn't move when there is no pressure on the prop - like on muffs in the driveway.

Could my problem be cable related as well as possibly shift interruption related?

Yes - either - or both - could be a problem. Easy test is to simply engage the switch by hand with the engine running and see if the engine dies. It should. If it doesn't, then the switch is bad or not wired correctly.