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Remove Honda bf40 prop shaft holder?

O

OregonApe

Member
Good grief, doing some basic maintenance on my 2000 BF40ay LRA before I sell it. Rebuilt the carb, removed the lower unit, rebuilt water pump, removed prop, found old fishing line, removed gross first seal. This is where it goes bad. I struggle with the second seal. My seal puller can't reach that deep. I thought I could drywall screw method it but the metal core prevents that. My brother in law comes along and breaks the prop shaft holder trying to pry out the seal with a screwdriver. Dang it.

41201-ZV5-000. #30 at https://www.boats.net/catalog/honda...ay-lra-bays-3200001-to-bays-3209999/propeller

So it looks like I have to buy a 12 tooth wrench attachment to remove the gear case end nut, #7 above. The wrench attachment appears to be this https://a.co/d/6dHgMrK

This stupid lower has seen salt so I'm guessing there is a decent chance I destroy the whole lower thanks to things fusing to each other.

Any suggestions? Am I on the right track?

https://imgur.com/a/Te9KFry
 
I'm no expert with those having never done one myself. But I would say yes, you're probably very close to disaster trying to unscrew that nut. I've read a couple of horror stories about what could happen to the case when you start trying to break it loose.

OTOH, yours doesn't look as horrible as some pictures I've seen so maybe you've got a decent chance.

Going verrrrrrry sloooooowly with it will be the key.

I would hit it with AERO KROIL and let set a month or two in the summer sun and when you're ready to give it the first try, hit it with KROIL again and heat that case up with a paint stripper hot air heat gun several times before beginning.

The secret to heat is not just the heating but also the cooling. That "cycling" from hot to cool (or cold if you have room in the freezer and the little lady won't behead you) helps break the bond and allows the penetrant to work itself in easier.

The longer and more often you can do this any chance of success you may have gets a little better.

OR, you can do what I used to do in my youth and just yank on it with all your might right away. It might POP loose or the case might explode into several pieces. Either way, with THAT technique there's no waiting. :)

In MY case I would bet on an explosion :(

Good luck.

P.S. PB Blaster and possibly a few other brand penetrants might work too but I have always had the most success with AERO KROIL.
AND....with PB Blaster smelling like wasp killer, KROIL might help with not ticking off the lady too :)
 
Anyone used one of these? They are sold on Amazon, this video shows how it works. I have several old car guys and a body shop guy that has one,they say 30-60 seconds to heat a nut or bolt to red hot. No flame, so can be used around gas tanks.

Some of the kits have a piece of the induction wire so you can do a custom size, maybe fit one on the outside of that aluminum case?

 
While I do agree with both the drilling (or cutting) of the nut and the use of an induction heating tool, I would just caution that there will be things you will want to consider and be cautious about with either technique.

Taking the nut out in pieces does appeal to me as the simplest, and obviously cheapest solution. Also waaaay faster than my method. But, the caveat, as I see it, is that accuracy would be of utmost importance. One slip with a drill or saw might damage the housing. Just very minor damage to the housing threads will likely set up a leak path that you might not be able to seal. Also, any hammering or chiseling to help remove the pieces of the nut should be done gently and carefully. All in all though, I agree it's a VERY viable solution.

The induction tool method would certainly work well to heat the housing but it's more effective and efficient on steel.

Aluminum, being non magnetic and highly conductive will be more difficult to heat up that way. Although, I might actually see that as a plus in this case because heating the housing too much wouldn't be good.

Cast aluminum melts at about half the temperature of steel at approximately 1220°f. as opposed to about 2200°f for steel. Since that tool is capable of heating the casting to above 600°f or half of melt temperature it could cause something known as annealing or softening of the aluminum to take place. I would not want that to occur to my gearcase. Keeping the heat down under 300°f is why I favor high watt heat guns for stuff like this.

Having said all that, I think these two suggestions are good and workable solutions if you give the one you choose careful thought.

Please let us know what you decide and how it works for you.

Good luck.
 
Yes racerone, you are right. I misspoke. There would be no leak path into or out of the case.

If carefully cut, do the pieces always come away cleanly on a badly corroded assembly?

If so, I would have to agree that is the best path forward.

Thanks for the correction.
 
Thanks for the responses all. Yeah, cutting it out seems the safest because I know beyond a shadow of a doubt that there is some corrosion that will make it a herculean task to unscrew the nut without breaking everything.

With that having been said, how do I go about doing that? I can't fit a dremel cut off disc in there, plus the angle would be weird. @racerone mentioned drilling it. Do you mean just center punching it and drilling? I feel like that would be a challenge to cut through but also to not also take out the threads. What is the process? Center punch, small drill bit and then increased the diameter until it cuts fully through?

On a related note, would it still be worth buying the proper 12 tooth wrench tool to tighten the new nut or could I get away with the old hammer and screwdriver?
 
Well, I went to harbor freight and got a couple packs of those diamond rotary bits. Of course, the 1/4 and 3/16” bits are too big for my rotary tool and the 1/16 is too small for the chuck to grip. So I get one bit per $5 pack.

High quality they are not. One bit gets me about one cut. Slow and steady wind the race I guess. I don't want to cut into the threads so I'm going slow.

https://imgur.com/a/492rcOR
 
Might just be me (usually is) but I would STILL use penetrant and heat to try and make sure that any corrosion bond is broken in the thread interface.

I have never done one but I suspect that, if there's enough bonding in there, you might still damage at least some thread in the case as you remove pieces of the nut.JGMO....just giving my opinion.

As far as using the wrench, I'm guessing that there's a tightening procedure to follow that would be listed in a service manual. Hopefully someone else here can provide that info for you. I imagine it's a Goldilocks thing.....not too tight....not too loose. I highly doubt it's "just finger tight"
or "beat it till it groans".
Again, jgmo.

Good luck
 
If you have a PRIME account, I bought some CARBIDE dremel bits from Amazon.

I thought "probably just Chinese junk and not carbide at all....but what the heck, they're cheap enough".

Well sir, those bits WERE hard and not junk at all! I've used them a bunch for about 6 or 7 years and still have all but one that I got jammed and broke. I bought another set with different head shapes too when I realized how good they were.


Just keep in mind, before you flame me, that it was several years ago and the quality could have changed. But I doubt it. They were cheaper then too....I only paid $10 for my set.

Even if they're not as hard as the Dremel brand (I think they ARE) they're still way harder than the cheapy hi speed steel stuff.
 
I uses this tool to my Honda BF50. Maybe the same as your proposal.

marinetech.com

Retaining Ring Wrench - 69mm OD, 12 Tooth

/* Font Imports */ @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;700&display=swap'); /* Global Container */ .custom-product-container { font-family: "Gotham Book", "Montserrat", sans-serif; color: #0A0A0A...
marinetech.com marinetech.com
 
jgmo said:
Might just be me (usually is) but I would STILL use penetrant and heat to try and make sure that any corrosion bond is broken in the thread interface.

I have never done one but I suspect that, if there's enough bonding in there, you might still damage at least some thread in the case as you remove pieces of the nut.JGMO....just giving my opinion.

As far as using the wrench, I'm guessing that there's a tightening procedure to follow that would be listed in a service manual. Hopefully someone else here can provide that info for you. I imagine it's a Goldilocks thing.....not too tight....not too loose. I highly doubt it's "just finger tight"
or "beat it till it groans".
Again, jgmo.

Good luck
Click to expand...

Thanks. That's a good idea. I went out there on my lunch break and started running a dremel etching bit with a tiny head around the edge of the nut and yeah, white corrosion goodness. I just wanted to get my layer of spray paint ( touched up and clear coated the paint on the lower in preparation to sell, of course I did that before trying to change the shaft seals....) out of the way so that the kroil could get down in there.

Also, I have bought some of those cheap chinese bits before. I have one of those little desktop CNC machines. They are hit or miss it seems. I did order some though. We'll see how it goes. I'll keep this thread updated for posterity.
 
ESa said:
I uses this tool to my Honda BF50. Maybe the same as your proposal.

marinetech.com

Retaining Ring Wrench - 69mm OD, 12 Tooth

/* Font Imports */ @import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Montserrat:wght@400;700&display=swap'); /* Global Container */ .custom-product-container { font-family: "Gotham Book", "Montserrat", sans-serif; color: #0A0A0A...
marinetech.com marinetech.com
Click to expand...

Yup, I ordered one of those plus the attachment piece that fits over your prop shaft. $120 is a lot for something I'll only use once or twice, but I'm sure someone will buy it when I'm done.
 
jgmo said:
Well, however it turns out, I will just say that you got guts for even trying.

Good luck.
Click to expand...
Thanks, I'll need it.

This is more desperation than bravery. No sense in spending $1700 on a whole new lower for a motor that is worth maybe 3 or 3.5 grand tops in good order (correct me if I'm wrong there). I looked for used lowers and they are even uglier than this one.
 
Ugh..... somehow the penetrating oil is leaking out of the water pump. The fiber gaskets are soaked. I can only assume that means the penetrating oil is making it's way down past whatever seals or O rings keep water out of the gears, into the gear housing, then out around the drive shaft seals. Glad I just replaced those fiber gaskets when I rebuilt the pump. Granted it is penetrating oil and is meant to make it's way past everything. I never had any gear oil get out of there.
 
Welp, she's dead Jim. I got the nut out easily enough. Those cheap Chinese carbide bits worked pretty well. Problem was that the threads were so corroded that after wire wheeling them a bit there were basically no threads left.

Also the prop shaft holder itself was massively corroded in place. I started cutting that out. That explains why I was getting penetrating oil leakage. There is just an O ring between the holder and the gear case.

Anyway, as I tried to break it loose a huge chunk of the side broke out. Turns out the previous owner had JB welded some big old cracks instead of having them welded.

Hopefully Amazon lets me return the unused wrench.

So do I try to find a used lower or do I just try to sell the motor as is. Motor runs great as I just rebuilt the carb stack.

https://imgur.com/a/9SS1NgU
 
In my opinion the material used in some newer outboards is not as good as motors built 30 years ago.----But folks love new products.
 
racerone said:
In my opinion the material used in some newer outboards is not as good as motors built 30 years ago.----But folks love new products.
Click to expand...

Yeah. That's not always the case, but from what I'm learning, this generation of Honda's all had massive corrosion issues with their lower units. I called a marine salvage place an hour away and they normally have everything you could think of and I barely got the words out of my mouth before the guy said he doesn't have one and basically will never have one because the BF40A and BF50A all have corrosion problems with their lowers. Called another place up by Seattle and they didn't have one, acknowledged corrosion issues and said they actually just had to order 2 new ones for a customer. That's like $3,600 plus tax for lowers. I would just take that money and find a bigger single motor that is newer.
 
In Sweden we repair the gear hose. Price ~600$, exl. shipping!
 

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