Tricky shifting into gear

[annageek]

We're just back from another fantastic couple of says out on the water, however we have a bit of a problem and was hoping someone would shed some light!!

If you shift into reverse, you have to shift the control lever to neutral, and then a bit towards forward to disengage reverse gear. In addition, from neutral (assuming it's not stuck in reverse!) getting forward gear is near impossible. As you advance the control lever, the engine just revs with no gear selection. You can just about get into forward gear, but you have to sort of rapidly advance the control lever to almost the full throttle forward position, and then back to nearly-but-not-quite neutral position. Obviously though, this gives the engine loads of revs, so forward gear engages with a hefty jolt... presumably putting untold strain on the poor dog clutch!

Once in gear, everything is fine. What could this be?

My thoughts are:

1. Control cables out of adjustment - although it's all been working OK up until this weekend, and no adjustment has been made.

2. Shift interrput switch playing up - i'm not convinced this is the problem, but hoping it is as its easy and quick to sort out!

3. Shift cable stretched (the one that goes from the shift plate down into the leg). - Sounds likely from what I've read, but I'm hoping it doesn't look particularly straight forward to change... how easy is it? Between us, we can get the leg off (and back on again) if we really have to, but will there be any special tools etc required for this job?

4. Something else.

Any input will be much appreciated!

Thanks so much in advance!!

Anna.

[annageek]

I'm an idiot... forgot to say... it's a mercruiser 3.0 with alpha one drive

[Xboatboyx]

Can't give any technical advice but we have a bayliner at work that that will stay in forward gear when in neutral so you have to knock it into reverse to get it out of gear.

[_Ed_]

Anna, have a look at the cables in the back as you shift the gear and see that the cables move as expected first. Sounds like there is some play in there somewhere.

[Ianfs]

Hi Anna,

I think Ed is on the right track and it could be the shift cables which are mounted to an exhaust elbow might have come out of either adjustment or something is broken. It doesn't need much, the adjustment is small.

I don't think its the interrupt switch or the shift cable at this stage. If you need to change the shift cable its fiddly but not impossible and I can talk you through it.

From your description of the problem though my interpretation is that instead of the shift from forward to reverse and visa versa happening when moving through neutral and then clonking in either side of it, it has moved to a more forward throttle position causing the revving. FYI the interupt switch is there to disengage the dog clutch rather than engage it. Consequently this may be why you have to jiggle the throttle at the moment to take her out of reverse.

When I get home I'll dig out some pictures of the shift adjustment plus a friend of mine from Aus has a You Tube vid of the adjustment.

I'm sure we can talk you through to a solution.

[annageek]

Excellent stuff... thanks for the input everyone.

We're just about to go down to the boat now to take a look. Will let you know what we find.

[Ianfs]

Except I've given you some wrong information. I said that the shift cables are mounted on the exhaust elbows. In fact they are mounted on the Carb Bracket..sorry Anna.

Have a very good look at them first, if you are you able to get internet at the boat, this is my mate Chris, he's Australian so please forgive the twang!! ..........However it might be helpful......

[youtube]-s_tgevX2aI [/youtube]

[annageek]

Aah! ian, next time you get in touch with Chris, let him know his videos are sport on! I watched his one on replacing the water pump in the alpha one drives. There are a lot of videos on Youtube regarding doing anything on boats, and Chris's are the only ones that are of any value IMO. They're so detailed - even down to the size of spanner/socket will be needed for each nut or bolt makes they super helpful, as you can make sure you have the tools you need before you turn up at the boat to realise you've left your xyz widget at home!

I actually watched that video last night, so had an idea what I was looking at before I started. Here's what I found.

1. First I tried to replicate the problem, and thankfully I could. With the engine not running, selecting reverse locked the prop from being spun by hand in the clockwise direction, le tthe prop rotate freely in both directions and, crucially, selecting forward did not lock the prop from being turned by hand in the anti-clockwise direction (which I would have expected). With forward selected, there was a slight clicky feeling when rotating the prop anti-clockwise, suggesting it was almost, but not quite catching/engaging with the dogs.

2. There was no evidence of anything looking bent, broken or in any way suspect around the shift plate.

3. I had taken no notes from the video, and had no reference with me, but I thought I'd have a fiddle anyway. I removed the shift cable from the shift plate. Sure enough, pushing it all the way to each end of its travel locked the prop in the appropriate direction when turned by hand. This therefore suggests that everything is working, it's just the adjustment is out for some reason (possibly a stretched cable)... unless I'm missing something?

4. I thought I'd have a fiddle with the barrel on the shift cable and see if I could improve things when it was fitted back to the shift plate. Sure enough, after a bit of trial and error, I had it so the prop locked correctly when shifted to both forward and reverse, and freed up completely when shifted out of both forward/reverse and into neutral.

5. Running the boat on the muffs, I confirmed that this remained true even under the engine's own steam. By pulsing into forward and reverse, everything seemed to work correctly. I also pressed the interrupt switch to ensure that was working - it was, so I presume this can now be discounted.

6. We had the boat dunked in the water, and with appropriate spring lines set up, tried again. It was tough to tell as there was a fair bit of current running but I'm about 90% sure it was working OK.

7. With the pontoon empty of other boats, we thought we'd try for real on the basis that docking shoudl be pretty low risk... even if we get stuck in gear or can't find gear at the right time etc. On the river, forward and reverse engaged perfectly, and again, I'm 90% certain that shifting into neutral (from either direction) was knocking out of gear. Sadly, with the current that last 10% of certainty was impossible to glean. In hindsight, I should have turned the boat perpendicular to the current and then tried! Oh well!

WoooHoooo! I've fixed it, I thought....

8. On docking, everything was fine - until I realised the boat was still pulling forward at tickover. It's weird, as it was only pulling forward very gently, and we were pojnting upstream (so with the current). We have just fitted a new 19" pitch Mercury Blackmax prop, so it could be that I'm just not used to the gentleness of the prop's force at tickover?

9. I tried to shift in and out again whilst tied to the pontoon. I seem to be able to get into forward/reverse with no drama at all. Getting out of reverse is fine too, but to get out of forward, I have to just nudge it into reverse slightly.

So, my fiddling did seem to improve things. To describe the adjustment on an arbitrary scale, it looks as if before I did anything we were at -5. I have adjusted towards 0, but perhaps gone slightly too far and am now at +1. SO...

1. Does it stand to reason that if I just back off my adjustment slightly, everything will be sorted and we'll reach the 0 point?

2. Have I adjusted the right thing, or have I improved things by adjusting the wrong part, meaning that the dogs won't be properly engaging now, or something?

3. Even if I have adjusted it all appropriately, and am on the right lines, I can't explain why it was out of adjustment (nothing has been intentionally changed since it it was working correctly). Therefore, assuming it is something like a stretched cable, is this likely to continue to stretch and forever need adjusting for... or even worse, just snap giving us zero control (most likely at a point where we will most likely need it)?

As it stands, I intend to completely reset everything in accordance with Chris's video. I expect (assuming it was originally set up correctly) that this will yield the same result as I described in my OP. Then, if necessary, i will repeat what I did today until I find the sweet spot where everything seems to work. If such a sweet spot cannot be found, does anybody have any idea what else needs to be investigated?

Many thanks in advance (again), and sorry for the super long post!

[Ianfs]

So, my fiddling did seem to improve things. To describe the adjustment on an arbitrary scale, it looks as if before I did anything we were at -5. I have adjusted towards 0, but perhaps gone slightly too far and am now at +1. SO...

I know you said it was a long post buy I read it all and this bit is the most significant. As I said before, the adjustment is quite small and Mercruiser work in 1/8" umm in new money about 3mm ish, consequently you may have to bring it back very slightly compared to the correct measurements to get to +/- 0 .

Now you have made the adjustments I think your cables may have stretched and you should change them, but if you can get the system to work, which I believe you will, don't change them until the end of the season. Oh and they wont snap, well no guarantee's, but they're stainless steel and unless the end connections are completely corroded which I doubt, they will be fine.

You will need to coat moving parts with some 2-4-C .

Make the fine adjustments and let me know how you get on.

[mark101]

That is so frustrating. I have had a similar experience but mine would not exit gear, which was fixed by a new interrupt switch.

Good guys on here and they'll definitely sort you out.


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