Crack in the gearboxHonda 50

"Hello all, Happy new year etc

"Hello all, Happy new year etc etc..

I am after some advice. Went out to fish the other day and on my return I had a look at the gear case.

The motor, a honda 50, is about a 2002 or 3 model. I use it heaps, maintain it at home and use a mechanic.

When i was washing it, I noted there is a crack in the gear case (see picture) It doesnt leak oil, as yet it doesnt go that far.

I pulled the prop off and noticed that there was a big lugged nut in there, and it appears at the bottom 1/4 on each side (so between 4 and 6 and 7 and 9 on the clock) the nut is not round, it appears to be putting some preassure on the exterior of the case so cracking the outside of the body.

How, without screwing everything up, can I get that big nut off? Anyone done it? Is it a regular thread and I can tap it anti clock wise to get it off? I have started loading it up with WD 40 in anticipation, and am slowly removing what looks like salt from between the nut and the body where it is pushing the body out of round....

Any ideas will be considered

Also can I hit the crack with the mig? If I go slow shouldnt warp it, anyone had experience in this? I wouldnt need gas would I?


Thanks

Chris Big nut"">Crack

"I just removed one on my 200

"I just removed one on my 200 Yami leg, the nut was breaking down and salt was in between it and the leg. For me it was lucky the nut appears to be made of a soft metal and it gave way instead of cracking the gear case. Mine came off anti-clockwise, yours should be the same. I used some heat and tapped with a punch. 1/4 of mine fell apart making it easier to force it free. If your a welder I'm sure you could fab up a crude tool to catch the tabs on opposite sides of the nut and have a long handle attached to give you the leverage to break it free. I know that you have to be more careful welding cast aluminum but I think you should be able to fix the casing. Keep the heat to a minimum so you don't kill the shaft seals. I know guys who rebuild old oil rig drill bits. They keep the part of the bit with the bearings submerged in water while they weld on new carbide tips....keeps the heat from destroying the bearings which makes the bit useless."

"Thanks for the advice Rollie,

"Thanks for the advice Rollie, I will try to tap it till it breaks I think, I cant seem to budge it no matter the tools or the heat and WD 40... I hope I dont break nothing else...

Chris"

"Hi, I don't have the expe

"Hi, I don't have the experience with this problem that would really qualify me to give you any advice. But, I've been hanging out here for a while to learn stuff and there are a couple of threads about the 50's doing this. Scroll down on the topics page to December 10th and look at the post by NORM. He talks about a redesign to eliminate this problem but it looks like you would have to buy a new gearcase complete. Then look at the stuff from him on 12-11. It might give you some insight as to what you might want to do.

BTW WD-40 is an excellent product...for cleaning your toolbox and lubing your doors. If you want something to loosen corrosion, use PB BLASTER.
Available at most automotive and hardware stores. If you want something that works like freakin' magic, Google AERO KROIL-usually need to order it through the mail and it is expensive but it is also MAGIC for loosening things up. Says so on the can; "THE OIL THAT CREEPS". I keep a gallon of it in my shop. Good luck."

"If you are calling the nut, t

"If you are calling the nut, the metal closest to the prop shaft with four tips sticking out...it is not a nut. It is the prop shaft holder.

The "nut" that holds it in is the ring on the outside with about 13 teeth. There is a thin ring with teeth just behind it (a claw washer), that has a couple of the teeth bent in to lock the outside "ring nut" (gearcase end nut). Straighten those tabs...then you have to unscrew it with a lock nut wrench (special tool). You may need to improvise.

Once the ring and the claw washer are removed, you have to put a puller on the prop shaft (held on by the prop nut) and pull the prop shaft and holder out.

Not easy without the right tools.

It is hard to say if you can weld the case or not. It depends on what you find when you take it apart.

Are you in an area where it freezes? I guess everybody is this week...

It may have filled with water and expanded due to the freezing water."

"Hi Jim,

I am in Australia,

"Hi Jim,

I am in Australia, they dont sell the stuff you recommended, but there are others which I will look into. Thanks for the advice on the other subjects to look at.

Hi Mike

I was calling the ring on the outside with the 13 teeth. I gently busted the bottom most piece of it out, by drilling it where the drain is. Once that was off I could gently move each end towards the prop shaft. The 13 teeth thing broke and came out, so all is good.

Thanks for letting me know it was a brittle thing Rollie, gave me the courage to cut and bend it secure in the thought it should break.

I think looking at it I should be able to get it welded no worries. I wont try it myself, Im not that good, but there are a few local people who should have a crack for me...

thanks for your advice. Unit still doesnt leak oil, but once its welded I might get the seals re done too.

Regards

Chris"

"Glad yours broke too, sounds

"Glad yours broke too, sounds exactly how I got mine out...bent the ends at the brake to the inside. Made if almost fall out, threads had lots of salt so it would have been a tough one to spin out. I did use a mini cutting wheel on a dremel to weaken the side of the nut that wasn't soften as much by corrosion...allowing me to bend that end towards the inside too."

"Oh, forgot to say, I live in

"Oh, forgot to say, I live in the tropics of Australia. Never ever ever gets colder than 17 C at night and we are usually about 32c during the day. No chance of freezing here,

Chris"

"My buddy just got back from a

"My buddy just got back from a month in Brisbane. He called my a couple of times from his wife's brother in laws house. I couldn't believe the bird chatter in the background while we talked. He says it started at 4:30 in the morning and went on all day. He slept real well the first day back home here, his comment...finally quiet and cool."

"Howdy there, I am after some

"Howdy there, I am after some more info.

Does the big 13 tooth nut tighten down all the way to the stainless tabbed washer thing?

I have made up a tool (you would all laugh if you saw it) to put the 13 tooth in, but for the life of me I cannot get it to tighten down. about 2 mm gap.

If it needs to go further I will take it to the honda bloke, but I best get it right before it goes in to be welded.

Thanks for any advice.

I cleaned all the threads out pretty well, but the hole is a little out of round, and my tool has become unstable...."

"Yes.

Check these things ou

"Yes.

Check these things out to be sure you put everything back correctly.

1. The propshaft holder should be inserted so that the word "up" on the end of one of the protrusions is in the 12:00 position.

2. Then put the claw washer in.

3. Then look on the 13 tooth nut for the word "off" on the side of it. When you find it, the word "off" should face out as you put the nut on. I think there may be a slight taper to the nut. If you put it in backwards, it may not tighten down.

Torque the nut to 89ft*lb (120 N*m)
Check to see that the claw washer and nut are aligned. If not aligned keep turning until aligned but no more than 111ft*lb (150 N*m).

Bend a couple of the tabs to lock the nut.

If the case is too far out of round, you may not be able to get everything to fit properly."

"Thanks Mike,

Got it in, th

"Thanks Mike,

Got it in, they had a special tool that they were able to use to get it in the one and a half turns it needed.

It is at the welders shop now for the next bit.

Thanks for all your help so far"

The flywheel should just lift

The flywheel should just lift off. The magnets are probably providing resistance. They are pretty strong. Get a couple of large screw drivers and pry very carefully to help you lift it. It should not take a lot of prying unless the flywheel has rusted on. It should wobble without much prying.

Having a buddy help you can make it easier.

The magnets are probably becoming delaminated and hitting the pickup coils.

Pretty common.

See this link for my repair. Not very professional. Get a new lower unit for your piece of mind and safety of your passengers. But if you are a stubborn old crank like me, read on...
LINK to my lower unit repair