OMC stuck in neutral

[bjp9860]

I was pulling a tuber around the lake doing some S turns when my boat seemed to suddenly fall out of gear. I was unable to put it back in gear, so a tow back to shore later, I'd like to try to figure out what's wrong.

I'm not great with boats or mechanical things, but I'll do my best to describe the situation. I have a 1985 Glasport with a 2.4L OMC Stringer, engine model 252STHROOM; click below for a larger picture:


Here is what the assembly that I think is attached to the end of the shift cable looks like in different control lever configurations (click on picture for larger version). First, in neutral:


At full forward throttle:


And full reverse throttle:


The engine will not turn the prop in any of these configurations. I can rev the engine in either direction, but the prop stays still. I used to feel a kind of "clunk" as the transmission engaged successfully when the boat was working, but I don't feel that now.

With the boat off, I can spin the prop freely by hand in either direction regardless of control lever position (neutral, full forward, full reverse).

Are there any tests I can perform to narrow down what exactly the problem is? Or is anyone confident they know what the problem is without further tests?

Thanks!
--Ben

 

[superbenk]

Re: OMC stuck in neutral

Sounds like a broken shift cable. That box you're taking pictures of is the shift converter box. It translates the in/out motion of the remote control cable into a shift cable that has two cables built into it that work in opposing directions. When you shift forward one cable in the shift cable between the converter box & the drive goes in toward the drive while the other comes out from the drive.

You can take the shift converter box cover off and look inside to make sure nothing is broken in there or has come loose (be careful to pay attention to how it's put together, how the cables run, etc. & don't lose any pieces). I'm more concerned that the shift cable itself (between the converter box & out drive) is broken, however. If that's the case you can expect to pay $600 for a new cable (maybe more now) and you'll have to take the outdrive apart to replace it (it's attaches to the shifting mechanism in the lower portion of the drive). Parts for the Stringer are getting harder to buy so you may have to dig around Ebay & others to find a new cable. Get yourself a shop manual if you don't have one.

 

[Scott Danforth]

Re: OMC stuck in neutral

could be broken shift cable, could be stripped splines on the 2-piece vertical shaft running thru the water pump.

BTDT, have the t-shirt

 

[Howard Sterndrive]

Re: OMC stuck in neutral

stripped splines on the 2-piece vertical shaft running thru the water pump.

that was my first thought.
Did the engine temp begin to rise above normal as you were trying to get it in gear?
If so, those splines are the likely culprit.

 

[bjp9860]

Re: OMC stuck in neutral

That box you're taking pictures of is the shift converter box. It translates the in/out motion of the remote control cable into a shift cable that has two cables built into it that work in opposing directions. When you shift forward one cable in the shift cable between the converter box & the drive goes in toward the drive while the other comes out from the drive.

Awesome, thanks for the explanation! I had assumed the remote cable was the "shift cable".

You can take the shift converter box cover off and look inside to make sure nothing is broken in there or has come loose (be careful to pay attention to how it's put together, how the cables run, etc. & don't lose any pieces).

Sounds good, will do!

I'm more concerned that the shift cable itself (between the converter box & out drive) is broken, however.

Yeah, I wouldn't be terribly surprised. I knew something like this could be an issue when I bought the boat. Thanks a ton for your guidance though -- I'll update the thread with any new information.

Did the engine temp begin to rise above normal as you were trying to get it in gear?
If so, those splines are the likely culprit.

The temperature goes slightly above center, but I didn't notice it being specifically linked to trying to put the boat in gear -- I'll check that more carefully.

 

[Scott Danforth]

Re: OMC stuck in neutral

if the splines are stipped (common stringer problem) then the water pump wont turn, which in turn wont push cooling water to the motor. if that happens, it will over heat quickly.

if it is a shift cable or a shaft, the lower has to come off to repair either.

 

[bjp9860]

Re: OMC stuck in neutral

Did the engine temp begin to rise above normal as you were trying to get it in gear?
If so, those splines are the likely culprit.

The temperature seems to stay within the normal zone when when I leave the engine throttled up for a minute or two. So, sounds like this is likely not the issue?

You can take the shift converter box cover off and look inside to make sure nothing is broken in there or has come loose (be careful to pay attention to how it's put together, how the cables run, etc. & don't lose any pieces).

Do you have a feeling for how likely it is for something in the converter box to be broken? And how likely do you guess it would be that I would find it very difficult to reassemble?

If that's the case you can expect to pay $600 for a new cable (maybe more now) and you'll have to take the outdrive apart to replace it (it's attaches to the shifting mechanism in the lower portion of the drive).

I've read perhaps 4 hours of shop time to do this repair (so maybe more like 16 for me) -- does that sound about right? And this is the part I want?
OMC Stringer Mechanical Shift Cable 982802 982810 INB Outboard Motor Boat Parts | eBay

Get yourself a shop manual if you don't have one.

This manual?
Clymer OMC Stern Drive Shop Manual 1964 1986 B730 | eBay

Thanks again!

 

[Scott Danforth]

Re: OMC stuck in neutral

read the stickies at the top of the forum. in there are links to on-line manuals http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/omc-information-334348.html

I would not buy anything until you confirm what is broken

I have R&R'd a shift cable in as little as 2 hours start to finish, so I agree with 4 hours. the lower HAS to come off to even get to the end of the cable in the foot. another thing you can do is pull the cover on the converter, pull the one pin, disconnect both ends of the shift cable and give a tug. if its broken, one end will come out in your hand.

I am still leaning toward stripped splines on the shaft

 

[vipertech]

Re: OMC stuck in neutral

Would it just slip out of gear if the cable broke or would it get stuck in that posistion? I have my drive torn down and replacing both shafts as mentioned above. After seeing what shape they were in and finding out they need to be replaced every three years. I would also look at yours as its a great possibility that they may have stripped out.

 

[Boomyal]

Re: OMC stuck in neutral

......and finding out they need to be replaced every three years. ......

Stripped out, they may be but a 3 year lifespan is way understated. My '79 hydro-mechanical went 30 years before being replaced. 10 of those years were hard driving, pushing a 20 footer with a 302. Even at that, they had not let loose yet. They were on the ragged edge but were only discovered with a general inspection teardown at that 30 year mark.

For bjp, I would definitely pull the cover off the shift converter, disconnect the shift cables and try to manipulate them manually. This would be step one in determining what the issue is.

 

[bjp9860]

Re: OMC stuck in neutral

another thing you can do is pull the cover on the converter, pull the one pin, disconnect both ends of the shift cable and give a tug. if its broken, one end will come out in your hand.

Sounds like a good diagnostic. Unfortunately I don't have the service manual yet; do you know of anything I should be careful of in particular that I might find difficult to reassemble when attempting to disassemble the converter?

 

[Boomyal]

Re: OMC stuck in neutral

Sounds like a good diagnostic. Unfortunately I don't have the service manual yet; do you know of anything I should be careful of in particular that I might find difficult to reassemble when attempting to disassemble the converter?

There is a procedure to disengage the cable housing from its entry anchor to the converter. There is a spring loaded pawl on the back of the entry snout. Once you have the cover off, you need to push the cable housing inward toward the box while you stick a small screwdriver underneath the pawl to disengage it from the cable housing. With the whole cable pushed inward against the spring loaded cable stop, this will give you the slack you need to disconnect the two cable ends from their mounting points. Once done, you can just relax your grip on the cable and pull it completely out. Leave the screw driver under the pawl. This will leave the two inner cables exposed so you can pull on them. If one of them comes out in your hand, it is broken.

The converter innards are pretty simple and there should be a threading diagram on the inside of the cover. Just keep track of which cable is which and do not lose any of the nylon bearing bushings that support the moving parts.

 

[superbenk]

Re: OMC stuck in neutral

Make sure the cables aren't crossed when you put it back together too.

 

[Boomyal]

Re: OMC stuck in neutral

Make sure the cables aren't crossed when you put it back together too.

Indeed, but it is not easy to tell when they are crossed. I studied this real hard the last time I had the drive off. Never could be entirely sure that they did not cross somewhere where they entered and exited the converter entry point.