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Gear rattle

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paiwong

New member
Hello,

We are experiencing a gear rattle in either the forward, neutral or reverse stance of the gear shift. This depends on the position of the 'shift rod joint' as indicated on the picture. If instructions are carried out according to the manual, the rattle remains. A video has been attached aswell.

Does anyone know how to solve this issue?



dGwdSvr.png
 
Well, that sure sounds like the clutch "dog" sections "bouncing" off of one another. The odd thing is that this is usually due to a misadjusted shift rod. But you have adjusted the rod by the book.

This could also occur if the shift rod gets bent for some reason. Many times the upper or "A" rod will bend when someone forces or, trys to force, the transmission into gear when the engine is off.

The clutch needs the main drive shaft to be rotating in order for the dogs (big, gear-like teeth) on the clutch to easily mesh with each other. If the shaft isn't rotating because the engine isn't running you must turn the propshaft by hand as you move the shift lever. If you don't supply this rotation when shifting, the clutch can get "gear-bound" and if it does, and additional force is applied to the shift lever, the upper rod usually bends.

If the upper rod gets a "bow" in it, obtaining a good rod adjustment is pretty unlikely.
The good news is that the rod can USUALLY be straightened without removing it from the outboard.

I'm not confident that is your problem in this instance but it has to be ruled out before considering the next move which involves removing the the propshaft assembly.
 
Dear jgmo and hondadude, I would like to thank you guys for your responses.

A bent upper shift rod might be the case -- I will check it out asap.
Is it possible that the lower shift unit (responsible clutch) is bent? It isn't cocentric with the hole on the lower unit (see first post image), instead it tends to 'stick' to the side of the hole.

Lower shift rod = part 8 on the list:
http://www.boats.net/parts/search/Honda/Outboard Engine/1998/BF15AW SA/VERTICAL SHAFT/parts.html
 
Well, I have to admit that I didn't initially realize that this was an older model and my advice was to look at the "A" shift rod (item 11 in the link you sent in your last post paiwong) because that's what usually bends om the later models. But, I'm sure hondadude is right about it is more likely to be the horizontal linkage he pointed out that connects to the shift lever because the older models are a bit different.

As to your question about the lower shift rod "B" being bent inside the gearcase, I'm not sure. I think that there could be something going on there but I can only guess as to what it might be.

I wonder if what I call the "shift shoe" (item 12, push rod, in your link) had gotten twisted sideways and that is why the rod is offset as it exits the housing. The only way to know for sure would be to go in and look. Which you will probably be doing if you don't find a problem externally.

Keep us posted. Because... we're always watching, always interested and always rooting for a successful outcome.
 
Hi, I've checked both Shiftrod A and the horizontal shift lever, both are straight, they don't seem to be bent. I can't tell if Shiftrod B is bent in an abnormal way since I have no (real life) comparison material.

However, I've noticed that the "shift shoe" is guided by rails inside the lower unit, which are both partially broken off, possibly causing a twisting motion of the shift shoe.
Could this be the root of the problem? If so - how does one fix this? The guide rails are part of the lower unit casting...
 
Well, I think you have found the problem. If the shoe is getting sideways due to the broken guide, the trans is likely not going solidly into gear. And, if it does go into gear it probably vibrates right back out.

I have never seen the guide broken and I'm guessing it would be next to impossible to reliably repair. My first instinct would be to start searching for a used replacement. I would also be looking to find a "parts outboard" and source the case from that. I find not running old Hondas for $200 or less. I can usually get them going and sell them but I have a couple I use for parts.

But, your's being a 98 15hp, I doubt anything I have would fit since I deal in the 7.5 and 10hp only because there are so many still around. The 15's are rarer in my opinion.

If I were to consider trying to fix one with a broken guide, I can envision a couple of different ways of going about it. But I can't really speculate on doing it until I looked it over carefully and assessed how much room I was working with.

I'm sorry to say it's looking like you're in a pretty tough spot with this failure. I don't see that the case is even sold separately and the entire assymbly is $823 plus shipping. Pretty steep for a 20 year old outboard.
 
Dear jgmo,

I cant find any short time solution other than replacing the lower unit casting with a new one, but they are rare and thus expensive when available.

We're thinking about running the outboard in its current state untill a new lower unit is found, would it significantly wear the gears or something else? -- what would you do?

Kind regards
 
Well.....that's a tough one to answer. It's a tough problem in a really tight space.

If I could have a close up look at it, I might...MIGHT....come up with an approach that I would think had a chance of working. But "flying blind" I can only come up with ideas that you may think are ridiculous. But....I'll give it a shot anyway.

If only one side of the "shoe guide" is broken or missing (where did those pieces go?) then you may be able to use the remaining guide as a model for finding a piece of material that you could use as a substitute for the missing one.

If the entire guide is broken, I'm not sure that I would even attempt a repair.

The space you have to work with is almost nil and effecting a repair that will last may involve trying to fit a piece with a sort of "foot" that could be attached with machine screws and nuts.
This would require drilling through the case and then sealing with gaskets under the screw heads or possibly industrial epoxy.

I'm going to stop right there and ask you if any of this makes any sense to you at all. I have lots of tools and experience that has me considering doing things that most would think a bit crazy.

Also, I found complete gear assembly on ebay that I want to research a bit to see if it might fit.

Talk later.

P.S. I looked into that transmission assembly and I think it might fit.

$545 or best offer. Seeing as just the case nrw is $850 or so, that's not a bad deal. But I would offer $400 and see what happens. It may end up being the easiest (and maybe cheapest) solution to your problem.

If $400 isn't in the budget, we go back to trying to come up with a "patch" repair and....to kerp looking for affordable parts. Having trouble with the ebay link. I will try again after I hear back from you. You may have already seen it anyway.

Let me know what you think
 
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Dear Jgmo,

I cant thank you enough for your extensive responses!
I'm from Europe (Netherlands) so the ebay auction wouldn't work for me -- however the complete lower units go for 300 - 400 dollars here aswell, but again hard to find.
(btw: bought the outboard in parts as a fix-her-upper so I've never actually sailed with it)

Both sides broke off more or less evenly, I've first tought of grinding the whole guide down and making new guides using some industrial 2k glue.
However..... the cramped space of the lower unit casting is indeed a pain to work with -- I have no idea how grind in such a small space.

So my second thought was to just sail with it, use the neutral and reverse gear as little as possible and hope for the best (while looking for 'new' lower unit casting).



What would you do?
 
In my younger days (I have since become the much maligned group known in America as "old white men") I used to spend quite a bit of time sailing a beautiful sloop known as Little Wing.

I had a Chrysler 6 hp, 2 cycle that ran GREAT. That is IF.....IF I could get it started!

The outboard, my old pappy would say, was "cold blooded". And, I was not anywhere near the mechanic I would one day become. Despite many hours of tinkering and scratching my head over that dang thing, I just couldn't figure out why it was so hard to get started. Very FRUSTRATING!

Because, once it started, it would run like a champ! Shut it off and it would start 2 hours later with one or two pulls! But....the next day? ....pull and pull and pull till your arms wanted to fall off. Then....FINALLY....VAROOOOM and off we'd go!

Well, one day I was pulling and pulling and...ENOUGH OF THIS!
I unscrewed the transom clamps, grabbed the handle, pulled it into the cockpit and carried it down into the house and shoved that sucker under the companionway where it sat and NEVER again saw the light of day.

Then?......I went sailing! Which is what I wanted to do all along and not spend 45 minutes fighting a stupid, stubborn old motor.

I went sailing and soon forgot about that outboard. I then became a much better sailor having to do EVERYTHING like leaving and returning to the slip with no motor. Sometimes with no breeze.

So, paiwong, to answer your question, I would sail with it my friend!

And have FUN!
 
Dear jgmo,

Thanks for sharing the story, great read! BUT... I think we have a misunderstanding (I don't know the correct term for 'riding a boat' hehe), with sailing I ment just 'riding the boat' by using the Honda in its current state.

I wish I could really sail though:D
 
Oh, that changes things. I assume that you are using the outboard to power a small skiff and NOT as an auxiliary on a sailboat. Is that correct?

If so, I might be reluctant to rely on the outboard as the only source of propulsion. I guess it come down to the size of the body of water, how far I was going offshore, how much boating traffic would be available to hail for assistance and whether or not I would have the ability to row or paddle the boat to shore.

Going offshore in lonely waters with possible large tides or currents to deal with should I be unable to get the outboard into gear would have me staying on land.

And then there is the risk of further damaging the transmission. If you're to have any hope of coming up with a repair, you certainly don't need any further damage taking place.

Another consideration is the value of the parts you have in there that are still okay. If you were to find a used unit, you could find that IT may be in need of some work as well. If you have still useable parts in your transmission you will want to save all you can in case you need them.

Ultimately it's your choice but I would have to say park it until you can work out something that will be a little more reliable and predictable.
 
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