Honda BF15a - Reverse gear crunching

To anyone who can help a complete Outboard novice..!

My reverse gear made a loud "crunching" sound the other day, and I lost reverse thrust.
This has happened before and I removed the lower unit, and looked at the gears (fearing the worst) but all seemed fine, and once I'd connected everything back together everything worked fine for a couple of months.

Connecting the linkage was a bit of guess work, as i have no other information to help.

Reading through the many posts on here (in an attempt to help myself first) I noticed that it could be the "Linkage" that's not set-up correctly, so how do you do this "by the book" - indeed which book..

Many thanks in anticipation, Nick

Hi Nick,
Not sure your problem is linkage setting, but maybe. Lots o people to help you here.
I do know the experts say "Helm" is the ONLY manual to use. Same as official HONDA manufacturers "Shop" manual.
Search manuals in this forum and someone has posted a link to a PDF download site that is "reputable". I did and it worked for $7. Paper copy closer to $50.
Sorry can't remember site address but its in forum somewhere!
Everyone says stay away Seloc ect manuals that have shaky or wrong info.

P.S. My manual definitely helped me clearly to hook up linkage. If memory serves, initial setting was 8mil of threads showing on linkage.

Oh yeah forgot, engine has to be in reverse too while adjusting. Think it depends if short or long shaft too. Mines a BF9.9.

tugcapitan said:

Oh yeah forgot, engine has to be in reverse too while adjusting. Think it depends if short or long shaft too. Mines a BF9.9.

Click to expand...

Hi Tugcapitan,

many thanks for your reply - as mentioned i'm a complete novice really so any pointers to what you think it might be would be really helpful too. If there's any other information that would help you draw some more suggestions just let me know

i have a long shaft BFA 15 (1998) so quite old.

as mentioned i had this problem before and after spending an hour or two playing withthe linkage nuts, it started to shift correctly, but maybe i'm missing something else?

once again thanks for your input, Nick

Hey Nick, I'm no expert. I've just started messing around with mine with the help of the good people on this forum. Diagnosis advice will have to come from them. However, can't say enough good about the manual. Troubleshooting guide, diagrams and everything. Just don't buy the wrong one! Helm or honda factory only shop manual.

Tugcapitan,

appreciate the advice, i shall start hunting round for the "right" manual & keep my fingers crossed.

all the best, Nickib

Here is what the manual says.....

Set the shift lever to FORWARD position, and screw in the shift rod joint (the long nut on the top shift rod)so that its edge is 3 mm out of the lower mount edge. The mount edge is part #11 http://www.boats.net/parts/search/Honda/Outboard Engine/2001/BF15A1 LA/EXTENSION CASE/parts.html

Move the shift lever from FORWARD to NEUTRAL, and attach shift rod B to the shift rod joint. Set the shift lever to the NEUTRAL position, and turn the shift rod joint (long nut) so that its edge is 6 mm out of the lower mount edge. Tighten the lock nut securely.

Check shifting by turning the prop by hand as you shift.

Hope that helps.

Mike

hondadude said:

Here is what the manual says.....

Set the shift lever to FORWARD position, and screw in the shift rod joint (the long nut on the top shift rod)so that its edge is 3 mm out of the lower mount edge. The mount edge is part #11 http://www.boats.net/parts/search/Honda/Outboard Engine/2001/BF15A1 LA/EXTENSION CASE/parts.html

Move the shift lever from FORWARD to NEUTRAL, and attach shift rod B to the shift rod joint. Set the shift lever to the NEUTRAL position, and turn the shift rod joint (long nut) so that its edge is 6 mm out of the lower mount edge. Tighten the lock nut securely.

Check shifting by turning the prop by hand as you shift.

Hope that helps.

Mike

Click to expand...

Hondadude,

That's really helpful thank you - i shall try the above and hopefully report back, with a thumbs up

regards, Nickib

Hondadude,

from what you've heard in my description does it sound reasonable that the shift rod is just not connected right - or could there be something more ominous?

regards, Nick

You need to start with the basics and make sure things are adjusted correctly.

Mike

I certainly agree with hondadude about verifying the shift rod adjustment and sticking to basics. First things first. But if you still have problems IN REVERSE after having done that, here are some things to consider:

I wanted to point out that when looking at this transmission, there are some "selective" parts for adjusting internal clearances. Namely, items 6 and 8 in the parts blow up below.

http://www.boats.net/parts/search/Honda/Outboard Engine/1998/BF15AW XAS/PROPELLER SHAFT/parts.html

When the transmission is in forward, the thrust of the prop "pushes" against the prop shaft and thrust washer. But when you put the transmission into reverse, the prop "pulls" on the shaft. This pulling action could cause the clutch to disengage from the reverse gear IF the shift shaft is incorrectly adjusted OR there is too much play in the system due to wear.

The clutch DOG slides on the prop shaft and is spring loaded forward. But the reverse gear will travel rearward, with the shaft, until it makes contact with selective shim #8 and stops. SOMETIMES a thicker #8 shim will solve a "jumps out of reverse" problem. But, you have to be careful adding shims because you can cause the prop shaft to "bind up" if you don't leave enough clearance in the system.

Also, if the transmission is allowed to "grind" too much, that will RAPIDLY wear the clutch dog edges and cause hard shift engagement. Sometimes up to the point that it just won't go into gear. When that happens, you will need to replace the offending gear AND the clutch dog. "LAZY" or slow gear selection causes this type of wear. When shifting your outboard, put the lever quickly, firmly and crisply into gear to minimize clutch "bounce".

Good luck.

jgmo,

Thats great information - as mentioned I'm an outboard novice, and looking at your diagram looks daunting - so first things first, i'll try and adjust the shift rod, if it continues to happen after that - are the parts mentioned easy to come by?

all the best, Nickib

Yes, the parts are available through the website I got that diagram from... www.boats.net

As a matter of fact, that IS the parts page you would order from. You can also get them through a local Honda dealer but would probably pay more money.

As far as working on the transmission, they are fairly simple devices for anyone with a mechanical background. But, I can understand how not just anyone would feel comfortable going in there and setting it up. You might need help from a competent mechanic.

One other thing about the shift rod adjustment though...Make sure that the adjustment nut doesn't have a tendency to "hang" on that "edge" of the mounting clamp that is referenced. It could do this if there are any bends in the rods that shouldn't be there. Make sure it isn't bent other than the bends that were put there at the factory. Those can be seen in the diagram I sent you. Any additional bends in the rod will shorten the overall length of the assembly. The selection of reverse gear relies on the rod being as long as it was originally. Because, when you select reverse, you are "pushing down" on the rod. If it is too short, due to unwanted bends, it won't push the clutch far enough to the rear to properly engage reverse gear.

Also, if after doing the adjustment exactly as hondadude explained, you still have issues try this:

You can try to "fudge" the adjustment to bias it toward reverse SLIGHTLY by not turning the adjustment nut until it is 3mm out of that ledge. You can experiment with 2mm or even 1.5mm to, in essence, make the shift rod slightly longer when PUSHED DOWN. The problem with getting carried away with this is that you may find that it will now not want to stay in FORWARD gear. So this "fudging" has it's limitations.

Good luck and I hope the "factory" adjustment solves your problem

jgmo,

once again many thanks for the advice, I had no idea that these forums could be so helpful. Having been a boat owner for about two years, I struggled to get any useful information about my Honda engine, until I found this site, its been excellent. Thanks to all that have read & replied with advice

A very Grateful Honda owner..NickiB

Yeah, the guys here will stick with you and try to help as long as you ask questions. Most problems seem to have happy endings but sometimes we get bucked off and a guy will need to seek professional help from a dealer or outboard shop. The sad thing is, there are lots of unscrupulous people posing as qualified outboard techs and so finding good, honest, local help can be difficult.

Keep us informed about that adjustment and the results thereof and we will forge on from there.

Welcome aboard the Forum!

YEAH BUDDY!
Congratulations and thanks for the "report"!

Oh dear its back again - the jumping out of reverse gear. one thing I noticed though, when i took apart the lower unit to examine inside the "oil" was creamy coloured, i guess indicating water. So my next question - could this be causing me the issues? - i know it certainly wont help. As mentioned above I appeared to have "fixed" the issue, but after running it for a few hours, the jump out of gear occurred.

again i would appreciate any pointers or advice - many thanks in advance

Hi nickb,

Well, it IS water intrusion...and...it CAN'T help. Water contamination destroys the lubricating ability of the gear oil and that leads to RAPID wear of the moving parts. But you know this already, don't you?

As I pointed out in this thread, post #12, there are some selective parts that are subject to wear but are also there to COMPENSATE for wear. So, the first order of business is to get the gear case sealed back up against water getting in and THEN figuring out why she's popping out of reverse.

Many times the reason for water intrusion is the PROP SHAFT SEAL has failed. Fishing line is the #1 culprit in prop shaft seal failure. A boater will do well to FREQUENTLY remove his prop and check for line or other "stringlike" debris wrapped around his prop shaft. Keeping that shaft clear of line keeps you FISHING!

But, it could also be a bad seal either at the shift rod or the main shaft. Sometimes it's as simple as having bad or missing seals at the fill and/or drain plugs. As long as the case itself isn't cracked, most leaks can be solved through the replacement of the seals.

The problem for most is that the ONLY reliable way to make SURE that you have a sealed case is to perform the PRESSURE...and then....the VACUUM tests. This is where a special FITTING is screwed into the case's fill screw hole and VERY LOW PRESSURE (around 3-5psi) shop air is introduced into the case. Any leaks would be evidenced by soap bubbles forming at the sealing points and or cracks in the case after being sprayed with a soap solution. (That's how I do it anyway.)

THEN...the pressure apparatus is removed and a hand vacuum pump is attached at the same location and a SLIGHT vacuum or NEGATIVE PRESSURE is introduced. If the case is sealed against vacuum leakage, the pressure should not RISE back to atmospheric for several minutes.

So, as you can see, this takes a couple of special tools and a little experience to "get it right". Neither of which the average boat owner possesses.

I went to the trouble of explaining how a sealed case is achieved not as a DIY tutorial but to arm you with enough KNOWLEDGE about the problem and the process so that you may go out and find a mechanic that has the tools and experience to help you.

Don't get me wrong, I don't want to discourage you from trying to do the work yourself but most people, after reading this, don't even want to try and then need to find a good WRENCH to give them a hand fixing their outboard.

Let me know how you will proceed.

And, GOOD LUCK!

JGMO - Great advice - and many thanks for your patience. My knowledge although slight when it comes to engines, is growing thanks to this great forum. Your right I don't possess any spe******t tools but from your explanation I have a much better understanding of what should / should happen. sorry to bother you with more questions - but how many seals are in the lower unit? - being in the UK, i cant seem to find anyone that sells these seals, i'll keep hunting around though.

all the best, Nick

Hi nickib,

Not bother AT ALL! This stuff is why we are ALL here. It would be a fairly boring site if no one ever asked any questions :~)

There are 5 places that water can enter the lower end because of sealing problem.

2 of these are the case drain plug (or screw) and the case fill plug. They have tiny Orings on them that can dry out or the screw itself can become loose. Pretty simple. However, I could NOT find an illustration or a part number for these Orings. They should be fairly easy to find in any competent, well stocked hardware store though.

THEN, things get much more complicated with the other 3 places.

These are:...the propshaft seal.....the shiftshaft seal......and the mainshaft seal. Below is a link for the transmission parts page. If you look at item #21, that is the prop shaft seal. It is the most COMMON place for failure due to fishing line wrapping behind the prop...as I've pointed out already. It is also the EASIEST of the three seals to replace. Although, I can tell you from experience, that it is easy to booger one up on installation too if you are inexperienced or don't have the proper tools. The easy part is that you can remove item #11, the "prop shaft holder" from the "bullet" or trans case and work on it on a bench. You may also note that the prop shaft holder is sold as an assembly and includes the seal as well as new bearings. The assembly is not killer expensive and is sometimes what I recommend, as an alternative to digging out the old seal and pressing in a new one, to someone not skilled in mechanics.

http://www.boats.net/parts/search/Honda/Outboard Engine/1998/BF15AW SA/PROPELLER SHAFT/parts.html

Next comes the shift shaft seal...or seals. In the link below find items 13, 27 and 28. You will need these three to seal that area should you determine that is where the water is entering. With all your shifting issues, it is a distinct possibility that something is... let's use the term...awry....in that area on your outboard. Inspection there may have you "killing two birds" as it were.

http://www.boats.net/parts/search/Honda/Outboard Engine/1998/BF15AW SA/VERTICAL SHAFT/parts.html

And then we come to the mainshaft seal. In the link below it is item #28. To replace this seal it is required that the gearcase be pretty much disassembled (except for the lower shift shaft) and the mainshaft removed. Not really all that bad of a job, but not for a novice or totally inexperienced mechanic unless you have gobs of time and really good organizational skills to keep all the parts laid out and not get them (or yourself) mixed up. Just a lot of holding your tongue "just so" if you know what I mean.

http://www.boats.net/parts/search/Honda/Outboard Engine/1998/BF15AW LAS/EXTENSION CASE/parts.html

Also, I've included a link to the FRONT page of the boats.net Honda parts webpage. On that page is an index where you can locate an approximation of your outboard...all American models as far as I know but most of this stuff is pretty much the same from what I can tell. Also, there is a button at the top of the page just right of center that says "INTERNATIONAL" and next to that is another button that says "SHIPPING". Hopefully you can find what you need here and get it shipped without taking out a mortgage on your home!


http://www.boats.net/parts/search/Honda/Outboard Engine/parts.html

Again, ask ALL the questions you want or need to......WE LOVE IT!

Good luck

Do the drain and fill plug in this model have an o ring or a nylon washer like the larger units? I have seen non honda (not nylon, sort of orange hard gasket paper) washers used and dry up and then let water in. The nylon washer doesn't dry up but it does crush down after use and can create a problem when reused. It's a cheap easy fix for about $1 and I recommend you have a pack of them at hand to replace when servicing the leg oil. I'm not 100% sure this applies to your model as I can't find the diagram or part number for them.

Hi Skronkman,

fairly sure the last time i had them undone, there were no washers at all - clearly that wont help. I'll pick some up and install them. Lots of good advice here again.

many thanks to all who have replied

all the best Nick

Hi all! I have been reading here and have the exact same issue. I would lime to know how you access the linkage adjustment rods. Thank you in advance for all your knowledge! I have learned so so much over the years on numerous subjects on numerous forums! To me, forums like this are a god send!